# htmx in a Nutshell

htmx is a library that allows you to access modern browser features directly from HTML, rather than using javascript.

To understand htmx, first lets take a look at an anchor tag:

<a href="/blog">Blog</a>
This anchor tag tells a browser:
“When a user clicks on this link, issue an HTTP GET request to ‘/blog’ and load the response content
into the browser window”.
With that in mind, consider the following bit of HTML:
<button hx-post="/clicked"
    hx-trigger="click"
    hx-target="#parent-div"
    hx-swap="outerHTML"
    Click Me!
</button>
This tells htmx:
“When a user clicks on this button, issue an HTTP POST request to ‘/clicked’ and use the content from the response
to replace the element with the id parent-div in the DOM”
htmx extends and generalizes the core idea of HTML as a hypertext, opening up many more possibilities directly
within the language:
Now any element, not just anchors and forms, can issue an HTTP request
Now any event, not just clicks or form submissions, can trigger requests
Now any HTTP verb, not just GET and POST, can be used
Now any element, not just the entire window, can be the target for update by the request
Note that when you are using htmx, on the server side you typically respond with HTML, not JSON.  This keeps you firmly
within the original web programming model,
using Hypertext As The Engine Of Application State
without even needing to really understand that concept.
It’s worth mentioning that, if you prefer, you can use the data- prefix when using htmx:
<a data-hx-post="/click">Click Me!</a>
Finally, Version 1 of htmx is still supported and supports IE11.
#1.x to 2.x Migration Guide
If you are migrating to htmx 2.x from htmx 1.x, please see the htmx 1.x migration guide.
If you are migrating to htmx from intercooler.js, please see the intercooler migration guide.
#Installing
Htmx is a dependency-free, browser-oriented javascript library. This means that using it is as simple as adding a <script>
tag to your document head.  There is no need for a build system to use it.
#Via A CDN (e.g. unpkg.com)
The fastest way to get going with htmx is to load it via a CDN. You can simply add this to 
your head tag and get going:
<script src="https://unpkg.com/htmx.org@2.0.0" integrity="sha384-wS5l5IKJBvK6sPTKa2WZ1js3d947pvWXbPJ1OmWfEuxLgeHcEbjUUA5i9V5ZkpCw" crossorigin="anonymous"></script>
An unminified version is also available for debugging as well:
<script src="https://unpkg.com/htmx.org@2.0.0/dist/htmx.js" integrity="sha384-Xh+GLLi0SMFPwtHQjT72aPG19QvKB8grnyRbYBNIdHWc2NkCrz65jlU7YrzO6qRp" crossorigin="anonymous"></script>
While the CDN approach is extremely simple, you may want to consider 
not using CDNs in production.
#Download a copy
The next easiest way to install htmx is to simply copy it into your project.
Download htmx.min.js from unpkg.com and add it to the appropriate directory in your project
and include it where necessary with a <script> tag:
<script src="/path/to/htmx.min.js"></script>
#npm
For npm-style build systems, you can install htmx via npm:
npm install htmx.org
After installing, you’ll need to use appropriate tooling to use node_modules/htmx.org/dist/htmx.js (or .min.js).
For example, you might bundle htmx with some extensions and project-specific code.
#Webpack
If you are using webpack to manage your javascript:
Install htmx via your favourite package manager (like npm or yarn)
Add the import to your index.js
import 'htmx.org';
If you want to use the global htmx variable (recommended), you need to inject it to the window scope:
Create a custom JS file
Import this file to your index.js (below the import from step 2)
import 'path/to/my_custom.js';
Then add this code to the file:
window.htmx = require('htmx.org');
Finally, rebuild your bundle
#AJAX
The core of htmx is a set of attributes that allow you to issue AJAX requests directly from HTML:
Each of these attributes takes a URL to issue an AJAX request to.  The element will issue a request of the specified
type to the given URL when the element is triggered:
<button hx-put="/messages">
    Put To Messages
</button>
This tells the browser:
When a user clicks on this button, issue a PUT request to the URL /messages and load the response into the button
#Triggering Requests
By default, AJAX requests are triggered by the “natural” event of an element:
input, textarea & select are triggered on the change event
form is triggered on the submit event
everything else is triggered by the click event
If you want different behavior you can use the hx-trigger
attribute to specify which event will cause the request.
Here is a div that posts to /mouse_entered when a mouse enters it:
<div hx-post="/mouse_entered" hx-trigger="mouseenter">
    [Here Mouse, Mouse!]
</div>
#Trigger Modifiers
A trigger can also have a few additional modifiers that change its behavior.  For example, if you want a request to only
happen once, you can use the once modifier for the trigger:
<div hx-post="/mouse_entered" hx-trigger="mouseenter once">
    [Here Mouse, Mouse!]
</div>
Other modifiers you can use for triggers are:
changed - only issue a request if the value of the element has changed
delay:<time interval> - wait the given amount of time (e.g. 1s) before
issuing the request.  If the event triggers again, the countdown is reset.
throttle:<time interval> - wait the given amount of time (e.g. 1s) before
issuing the request.  Unlike delay if a new event occurs before the time limit is hit the event will be discarded,
so the request will trigger at the end of the time period.
from:<CSS Selector> - listen for the event on a different element.  This can be used for things like keyboard shortcuts.
You can use these attributes to implement many common UX patterns, such as Active Search:
<input type="text" name="q"
    hx-get="/trigger_delay"
    hx-trigger="keyup changed delay:500ms"
    hx-target="#search-results"
    placeholder="Search..."
<div id="search-results"></div>
This input will issue a request 500 milliseconds after a key up event if the input has been changed and inserts the results
into the div with the id search-results.
Multiple triggers can be specified in the hx-trigger attribute, separated by commas.
#Trigger Filters
You may also apply trigger filters by using square brackets after the event name, enclosing a javascript expression that
will be evaluated.  If the expression evaluates to true the event will trigger, otherwise it will not.
Here is an example that triggers only on a Control-Click of the element
<div hx-get="/clicked" hx-trigger="click[ctrlKey]">
    Control Click Me
</div>
Properties like ctrlKey will be resolved against the triggering event first, then against the global scope.  The
this symbol will be set to the current element.
#Special Events
htmx provides a few special events for use in hx-trigger:
load - fires once when the element is first loaded
revealed - fires once when an element first scrolls into the viewport
intersect - fires once when an element first intersects the viewport.  This supports two additional options:
root:<selector> - a CSS selector of the root element for intersection
threshold:<float> - a floating point number between 0.0 and 1.0, indicating what amount of intersection to fire the event on
You can also use custom events to trigger requests if you have an advanced use case.
#Polling
If you want an element to poll the given URL rather than wait for an event, you can use the every syntax
with the hx-trigger attribute:
<div hx-get="/news" hx-trigger="every 2s"></div>
This tells htmx
Every 2 seconds, issue a GET to /news and load the response into the div
If you want to stop polling from a server response you can respond with the HTTP response code 286
and the element will cancel the polling.
#Load Polling
Another technique that can be used to achieve polling in htmx is “load polling”, where an element specifies
a load trigger along with a delay, and replaces itself with the response:
<




    
div hx-get="/messages"
    hx-trigger="load delay:1s"
    hx-swap="outerHTML"
</div>
If the /messages end point keeps returning a div set up this way, it will keep “polling” back to the URL every
second.
Load polling can be useful in situations where a poll has an end point at which point the polling terminates, such as
when you are showing the user a progress bar.
#Request Indicators
When an AJAX request is issued it is often good to let the user know that something is happening since the browser
will not give them any feedback.  You can accomplish this in htmx by using htmx-indicator class.
The htmx-indicator class is defined so that the opacity of any element with this class is 0 by default, making it invisible
but present in the DOM.
When htmx issues a request, it will put a htmx-request class onto an element (either the requesting element or
another element, if specified).  The htmx-request class will cause a child element with the htmx-indicator class
on it to transition to an opacity of 1, showing the indicator.
<button hx-get="/click">
    Click Me!
    <img class="htmx-indicator" src="/spinner.gif">
</button>
Here we have a button.  When it is clicked the htmx-request class will be added to it, which will reveal the spinner
gif element.  (I like SVG spinners these days.)
While the htmx-indicator class uses opacity to hide and show the progress indicator, if you would prefer another mechanism
you can create your own CSS transition like so:
.htmx-indicator{
    ;
.htmx-request .htmx-indicator{
    display:inline;
.htmx-request.htmx-indicator{
    display:inline;
If you want the htmx-request class added to a different element, you can use the hx-indicator
attribute with a CSS selector to do so:
    <button hx-get="/click" hx-indicator="#indicator">
        Click Me!
    </button>
    <img id="indicator" class="htmx-indicator" src="/spinner.gif"/>
</div>
Here we call out the indicator explicitly by id.  Note that we could have placed the class on the parent div as well
and had the same effect.
You can also add the disabled attribute to
elements for the duration of a request by using the hx-disabled-elt attribute.
#Targets
If you want the response to be loaded into a different element other than the one that made the request, you can
use the hx-target attribute, which takes a CSS selector.  Looking back at our Live Search example:
<input type="text" name="q"
    hx-get="/trigger_delay"
    hx-trigger="keyup delay:500ms changed"
    hx-target="#search-results"
    placeholder="Search..."
<div id="search-results"></div>
You can see that the results from the search are going to be loaded into div#search-results, rather than into the
input tag.
#Extended CSS Selectors
hx-target, and most attributes that take a CSS selector, support an “extended” CSS syntax:
You can use the this keyword, which indicates that the element that the hx-target attribute is on is the target
The closest <CSS selector> syntax will find the closest
ancestor element or itself, that matches the given CSS selector.
(e.g. closest tr will target the closest table row to the element)
The next <CSS selector> syntax will find the next element in the DOM matching the given CSS selector.
The previous <CSS selector> syntax will find the previous element in the DOM the given CSS selector.
find <CSS selector> which will find the first child descendant element that matches the given CSS selector.
(e.g find tr would target the first child descendant row to the element)
In addition, a CSS selector may be wrapped in < and /> characters, mimicking the
query literal syntax of hyperscript.
Relative targets like this can be useful for creating flexible user interfaces without peppering your DOM with lots
of id attributes.
#Swapping
htmx offers a few different ways to swap the HTML returned into the DOM.  By default, the content replaces the
innerHTML of the target element.  You can modify this by using the hx-swap attribute
with any of the following values:
Attribute
Description

hx-get
Issues a GET request to the given URL
hx-post
Issues a POST request to the given URL
hx-put
Issues a PUT request to the given URL
hx-patch
Issues a PATCH request to the given URL
hx-delete
Issues a DELETE request to the given URL

#Morph Swaps
In addition to the standard swap mechanisms above, htmx also supports morphing swaps, via extensions.  Morphing swaps
attempt to merge new content into the existing DOM, rather than simply replacing it.  They often do a better job
preserving things like focus, video state, etc. by mutating existing nodes in-place during the swap operation, at the
cost of more CPU.
The following extensions are available for morph-style swaps:
Idiomorph - A morphing algorithm created by the htmx developers.
Morphdom Swap - Based on the morphdom,
the original DOM morphing library.
Alpine-morph - Based on the alpine morph plugin, plays
well with alpine.js
#View Transitions
The new, experimental View Transitions API
gives developers a way to create an animated transition between different DOM states.  It is still in active development
and is not available in all browsers, but htmx provides a way to work with this new API that falls back to the non-transition
mechanism if the API is not available in a given browser.
You can experiment with this new API using the following approaches:
Set the htmx.config.globalViewTransitions config variable to true to use transitions for all swaps
Use the transition:true option in the hx-swap attribute
If an element swap is going to be transitioned due to either of the above configurations, you may catch the
htmx:beforeTransition event and call preventDefault() on it to cancel the transition.
View Transitions can be configured using CSS, as outlined in the Chrome documentation for the feature.




    
You can see a view transition example on the Animation Examples page.
#Swap Options
The hx-swap attribute supports many options for tuning the swapping behavior of htmx.  For
example, by default htmx will swap in the title of a title tag found anywhere in the new content.  You can turn this
behavior off by setting the ignoreTitle modifier to true:
    <button hx-post="/like" hx-swap="outerHTML ignoreTitle:true">Like</button>
The modifiers available on hx-swap are:
Name
Description

innerHTML
the default, puts the content inside the target element
outerHTML
replaces the entire target element with the returned content
afterbegin
prepends the content before the first child inside the target
beforebegin
prepends the content before the target in the target’s parent element
beforeend
appends the content after the last child inside the target
afterend
appends the content after the target in the target’s parent element
delete
deletes the target element regardless of the response
none
does not append content from response (Out of Band Swaps and Response Headers will still be processed)
















All swap modifiers appear after the swap style is specified, and are colon-separated.
See the hx-swap documentation for more details on these options.
#Synchronization
Often you want to coordinate the requests between two elements.  For example, you may want a request from one element
to supersede the request of another element, or to wait until the other element’s request has finished.
htmx offers a hx-sync attribute to help you accomplish this.
Consider a race condition between a form submission and an individual input’s validation request in this HTML:
<form hx-post="/store">
    <input id="title" name="title" type="text"
        hx-post="/validate"
        hx-trigger="change">
    <button type="submit">Submit</button>
</form>
Without using hx-sync, filling out the input and immediately submitting the form triggers two parallel requests to
/validate and /store.
Using hx-sync="closest form:abort" on the input will watch for requests on the form and abort the input’s request if
a form request is present or starts while the input request is in flight:
<form hx-post="/store">
    <input id="title" name="title" type="text"
        hx-post="/validate"
        hx-trigger="change"
        hx-sync="closest form:abort">
    <button type="submit">Submit</button>
</form>
This resolves the synchronization between the two elements in a declarative way.
htmx also supports a programmatic way to cancel requests: you can send the htmx:abort event to an element to
cancel any in-flight requests:
<button id="request-button" hx-post="/example">
    Issue Request
</button>
<button onclick="htmx.trigger('#request-button', 'htmx:abort')">
    Cancel Request
</button>
More examples and details can be found on the hx-sync attribute page.
#CSS Transitions
htmx makes it easy to use CSS Transitions without
javascript.  Consider this HTML content:
<div id="div1">Original Content</div>
Imagine this content is replaced by htmx via an ajax request with this new content:
<div id="div1" class="red">New Content</div>
Note two things:
The div has the same id in the original and in the new content
The red class has been added to the new content
Given this situation, we can write a CSS transition from the old state to the new state:
.red {
    color: red;
    transition: all ease-in 1s ;
When htmx swaps in this new content, it will do so in such a way that the CSS transition will apply to the new content,
giving you a nice, smooth transition to the new state.
So, in summary, all you need to do to use CSS transitions for an element is keep its id stable across requests!
You can see the Animation Examples for more details and live demonstrations.
#Details
To understand how CSS transitions actually work in htmx, you must understand the underlying swap & settle model that htmx uses.
When new content is received from a server, before the content is swapped in, the existing
content of the page is examined for elements that match by the id attribute.  If a match
is found for an element in the new content, the attributes of the old content are copied
onto the new element before the swap occurs.  The new content is then swapped in, but with the
old attribute values.  Finally, the new attribute values are swapped in, after a “settle” delay
(20ms by default).  A little crazy, but this is what allows CSS transitions to work without any javascript by
the developer.
#Out of Band Swaps
If you want to swap content from a response directly into the DOM by using the id attribute you can use the
hx-swap-oob attribute in the response html:
<div id="message" hx-swap-oob="true">Swap me directly!</div>
Additional Content
In this response, div#message would be swapped directly into the matching DOM element, while the additional content
would be swapped into the target in the normal manner.
You can use this technique to “piggy-back” updates on other requests.
#Troublesome Tables
Table elements can be problematic when combined with out of band swaps, because, by the HTML spec, many can’t stand on
their own in the DOM (e.g. <tr> or <td>).
To avoid this issue you can use a template tag to encapsulate these elements:
<template>
  <tr id




    
="message" hx-swap-oob="true"><td>Joe</td><td>Smith</td></tr>
</template>
#Selecting Content To Swap
If you want to select a subset of the response HTML to swap into the target, you can use the hx-select
attribute, which takes a CSS selector and selects the matching elements from the response.
You can also pick out pieces of content for an out-of-band swap by using the hx-select-oob
attribute, which takes a list of element IDs to pick out and swap.
#Preserving Content During A Swap
If there is content that you wish to be preserved across swaps (e.g. a video player that you wish to remain playing
even if a swap occurs) you can use the hx-preserve
attribute on the elements you wish to be preserved.
#Parameters
By default, an element that causes a request will include its value if it has one.  If the element is a form it
will include the values of all inputs within it.
As with HTML forms, the name attribute of the input is used as the parameter name in the request that htmx sends.
Additionally, if the element causes a non-GET request, the values of all the inputs of the nearest enclosing form
will be included.
If you wish to include the values of other elements, you can use the hx-include attribute
with a CSS selector of all the elements whose values you want to include in the request.
If you wish to filter out some parameters you can use the hx-params attribute.
Finally, if you want to programmatically modify the parameters, you can use the htmx:configRequest
event.
#File Upload
If you wish to upload files via an htmx request, you can set the hx-encoding attribute to
multipart/form-data.  This will use a FormData object to submit the request, which will properly include the file
in the request.
Note that depending on your server-side technology, you may have to handle requests with this type of body content very
differently.
Note that htmx fires a htmx:xhr:progress event periodically based on the standard progress event during upload,
which you can hook into to show the progress of the upload.
See the examples section for more advanced form patterns, including progress bars and error handling.
#Extra Values
You can include extra values in a request using the hx-vals (name-expression pairs in JSON format) and
hx-vars attributes (comma-separated name-expression pairs that are dynamically computed).
#Confirming Requests
Often you will want to confirm an action before issuing a request.  htmx supports the hx-confirm
attribute, which allows you to confirm an action using a simple javascript dialog:
<button hx-delete="/account" hx-confirm="Are you sure you wish to delete your account?">
    Delete My Account
</button>
Using events you can implement more sophisticated confirmation dialogs.  The confirm example
shows how to use sweetalert2 library for confirmation of htmx actions.
#Confirming Requests Using Events
Another option to do confirmation with is via the htmx:confirm event event.  This event
is fired on every trigger for a request (not just on elements that have a hx-confirm attribute) and can be used
to implement asynchronous confirmation of the request.
Here is an example using sweet alert on any element with a confirm-with-sweet-alert='true' attribute on it:
document.body.addEventListener('htmx:confirm', function(evt) {
  if (evt.target.matches("[confirm-with-sweet-alert='true']")) {
    evt.preventDefault();
    swal({
      title: "Are you sure?",
      text: "Are you sure you are sure?",
      icon: "warning",
      buttons: true,
      dangerMode: true,
    }).then((confirmed) => {
      if (confirmed) {
        evt.detail.issueRequest();
#Attribute Inheritance
Most attributes in htmx are inherited: they apply to the element they are on as well as any children elements.  This
allows you to “hoist” attributes up the DOM to avoid code duplication.  Consider the following htmx:
<button hx-delete="/account" hx-confirm="Are you sure?">
    Delete My Account
</button>
<button hx-put="/account" hx-confirm="Are you sure?">
    Update My Account
</button>
Here we have a duplicate hx-confirm attribute.  We can hoist this attribute to a parent element:
<div hx-confirm="Are you sure?">
    <button hx-delete="/account">
        Delete My Account
    </button>
    <button hx-put="/account">
        Update My Account
    </button>
</div>
This hx-confirm attribute will now apply to all htmx-powered elements within it.
Sometimes you wish to undo this inheritance.  Consider if we had a cancel button to this group, but didn’t want it to
be confirmed.  We could add an unset directive on it like so:
<div hx-confirm="Are you sure?">
    <button hx-delete="/account">
        Delete My Account
    </button>
    <button hx-put="/account">
        Update My Account
    </button>
    <button hx-confirm="unset" hx-get="/">
        Cancel
    </button>
</div>
The top two buttons would then show a confirm dialog, but the bottom cancel button would not.
Inheritance can be disabled on a per-element and per-attribute basis using the
hx-disinherit attribute.
If you wish to disable attribute inheritance entirely, you can set the htmx.config.disableInheritance configuration
variable to true.   This will disable inheritance as a default, and allow you to specify inheritance explicitly
with the hx-inherit attribute.
#Boosting
Htmx supports “boosting” regular HTML anchors and forms with the hx-boost attribute.  This
attribute will convert all anchor tags and forms into AJAX requests that, by default, target the body of the page.
Here is an example:
<div hx-boost="true">
    <a href="/blog">Blog</a>
</div>
The anchor tag in this div will issue an AJAX GET request to /blog and swap the response into the body tag.
#Progressive Enhancement
A feature of hx-boost is that it degrades gracefully if javascript is not enabled: the links and forms continue
to work, they simply don’t use ajax requests.  This is known as
Progressive Enhancement, and it allows
a wider audience to use your site’s functionality.
Other htmx patterns can be adapted to achieve progressive enhancement as well, but they will require more thought.
Consider the active search example.  As it is written, it will not degrade gracefully:
someone who does not have javascript enabled will not be able to use this feature. This is done for simplicity’s sake,
to keep the example as brief as possible.
However, you could wrap the htmx-enhanced input in a form element:
<form action="/search" method="POST">
    <input class="form-control" type="search"
        name="search" placeholder="Begin typing to search users..."
        hx-post="/search"
        hx-trigger="keyup changed delay:500ms, search"
        hx-target="#search-results"
        hx-indicator=".htmx-indicator">
</form>
With this in place, javascript-enabled clients would still get the nice active-search UX, but non-javascript enabled
clients would be able to hit the enter key and still search.  Even better, you could add a “Search” button as well.
You would then need to update the form with an hx-post that mirrored the action attribute, or perhaps use hx-boost
on it.
You would need to check on the server side for the HX-Request header to differentiate between an htmx-driven and a
regular request, to determine exactly what to render to the client.
Other patterns can be adapted similarly to achieve the progressive enhancement needs of your application.
As you can see, this requires more thought and more work.  It also rules some functionality entirely out of bounds.
These tradeoffs must be made by you, the developer, with respect to your projects goals and audience.
Accessibility is a concept
closely related to progressive enhancement.  Using progressive enhancement techniques such as hx-boost will make your
htmx application more accessible to a wide array of users.
htmx-based applications are very similar to normal, non-AJAX driven web applications because htmx is HTML-oriented.
As such, the normal HTML accessibility recommendations apply.  For example:
Use semantic HTML as much as possible (i.e. the right tags for the right things)
Ensure focus state is clearly visible
Associate text labels with all form fields
Maximize the readability of your application with appropriate fonts, contrast, etc.
#Web Sockets & SSE
Web Sockets and Server Sent Events (SSE) are supported via extensions.  Please see
the SSE extension and WebSocket extension
pages to learn more.




    

#History Support
Htmx provides a simple mechanism for interacting with the browser history API:
If you want a given element to push its request URL into the browser navigation bar and add the current state of the page
to the browser’s history, include the hx-push-url attribute:
<a hx-get="/blog" hx-push-url="true">Blog</a>
When a user clicks on this link, htmx will snapshot the current DOM and store it before it makes a request to /blog.
It then does the swap and pushes a new location onto the history stack.
When a user hits the back button, htmx will retrieve the old content from storage and swap it back into the target,
simulating “going back” to the previous state.  If the location is not found in the cache, htmx will make an ajax
request to the given URL, with the header HX-History-Restore-Request set to true, and expects back the HTML needed
for the entire page.  Alternatively, if the htmx.config.refreshOnHistoryMiss config variable is set to true, it will
issue a hard browser refresh.
NOTE: If you push a URL into the history, you must be able to navigate to that URL and get a full page back!
A user could copy and paste the URL into an email, or new tab.  Additionally, htmx will need the entire page when restoring
history if the page is not in the history cache.
#Specifying History Snapshot Element
By default, htmx will use the body to take and restore the history snapshot from.  This is usually the right thing, but
if you want to use a narrower element for snapshotting you can use the hx-history-elt
attribute to specify a different one.
Careful: this element will need to be on all pages or restoring from history won’t work reliably.
#Undoing DOM Mutations By 3rd Party Libraries
If you are using a 3rd party library and want to use the htmx history feature, you will need to clean up the DOM before
a snapshot is taken.  Let’s consider the Tom Select library, which makes select elements
a much richer user experience.  Let’s set up TomSelect to turn any input element with the .tomselect class into a rich
select element.
First we need to initialize elements that have the class in new content:
htmx.onLoad(function (target) {
    // find all elements in the new content that should be
    // an editor and init w/ TomSelect
    var editors = target.querySelectorAll(".tomselect")
            .forEach(elt => new TomSelect(elt))
This will create a rich selector for all input elements that have the .tomselect class on it.  However, it mutates
the DOM and we don’t want that mutation saved to the history cache, since TomSelect will be reinitialized when the
history content is loaded back into the screen.
To deal with this, we need to catch the htmx:beforeHistorySave event and clean out the TomSelect mutations by calling
destroy() on them:
htmx.on('htmx:beforeHistorySave', function() {
    // find all TomSelect elements
    document.querySelectorAll('.tomSelect')
            .forEach(elt => elt.tomselect.destroy()) // and call destroy() on them
This will revert the DOM to the original HTML, thus allowing for a clean snapshot.
#Disabling History Snapshots
History snapshotting can be disabled for a URL by setting the hx-history attribute to false
on any element in the current document, or any html fragment loaded into the current document by htmx. This can be used
to prevent sensitive data entering the localStorage cache, which can be important for shared-use / public computers.
History navigation will work as expected, but on restoration the URL will be requested from the server instead of the
local history cache.
#Requests & Responses
Htmx expects responses to the AJAX requests it makes to be HTML, typically HTML fragments (although a full HTML
document, matched with a hx-select tag can be useful too).  Htmx will then swap the returned
HTML into the document at the target specified and with the swap strategy specified.
Sometimes you might want to do nothing in the swap, but still perhaps trigger a client side event (see below).
For this situation, by default, you can return a 204 - No Content response code, and htmx will ignore the content of
the response.
In the event of an error response from the server (e.g. a 404 or a 501), htmx will trigger the htmx:responseError
event, which you can handle.
In the event of a connection error, the htmx:sendError event will be triggered.
#Configuring Response Handling
You can configure the above behavior of htmx by mutating or replacing the htmx.config.responseHandling array.  This
object is a collection of JavaScript objects defined like so:
    responseHandling: [
        {code:"204", swap: false},   // 204 - No Content by default does nothing, but is not an error
        {code:"[23]..", swap: true}, // 200 & 300 responses are non-errors and are swapped
        {code:"[45]..", swap: false, error:true}, // 400 & 500 responses are not swapped and are errors
When htmx receives a response it will iterate in order over the htmx.config.responseHandling array and test if the
code property of a given object, when treated as a Regular Expression, matches the current response.  If an entry
does match the current response code, it will be used to determine if and how the response will be processed.
The fields available for response handling configuration on entries in this array are:
code - a String representing a regular expression that will be tested against response codes.
swap - true if the response should be swapped into the DOM, false otherwise
error - true if htmx should treat this response as an error
ignoreTitle - true if htmx should ignore title tags in the response
select - A CSS selector to use to select content from the response
target - A CSS selector specifying an alternative target for the response
swapOverride - An alternative swap mechanism for the response
#Configuring Response Handling Examples
As an example of how to use this configuration, consider a situation when a server-side framework responds with a
422 - Unprocessable Entity response when validation errors occur.  By default, htmx will ignore the response, 
since it matches the Regular Expression [45]... 
Using the meta config mechanism for configuring responseHandling, we could add the following
config:
<meta name="htmx-config" content='{code:"204", swap: false},   // 204 - No Content by default does nothing, but is not an error
                                  {code:"[23]..", swap: true}, // 200 & 300 responses are non-errors and are swapped
                                  {code:"422", swap: true}, // 422 responses are swapped
                                  {code:"[45]..", swap: false, error:true}, // 400 & 500 responses are not swapped and are errors'>
If you wanted to swap everything, regardless of HTTP response code, you could use this configuration:
<meta name="htmx-config" content='{code:".*", swap: true}, // all responses are swapped'>
Finally, it is worth considering using the Response Targets
extension, which allows you to configure the behavior of response codes declaratively via attributes.
#CORS
When using htmx in a cross origin context, remember to configure your web
server to set Access-Control headers in order for htmx headers to be visible
on the client side.
Access-Control-Allow-Headers (for request headers)
Access-Control-Expose-Headers (for response headers)
See all the request and response headers that htmx implements.
#Request Headers
htmx includes a number of useful headers in requests:
Option
Description

transition
true or false, whether to use the view transition API for this swap
swap
The swap delay to use (e.g. 100ms) between when old content is cleared and the new content is inserted
settle
The settle delay to use (e.g. 100ms) between when new content is inserted and when it is settled
ignoreTitle
If set to true, any title found in the new content will be ignored and not update the document title
scroll
top or bottom, will scroll the target element to its top or bottom
show
top or bottom, will scroll the target element’s top or bottom into view






#Response Headers
htmx supports some htmx-specific response headers:




    
HX-Location - allows you to do a client-side redirect that does not do a full page reload
HX-Push-Url - pushes a new url into the history stack
HX-Redirect - can be used to do a client-side redirect to a new location
HX-Refresh - if set to “true” the client-side will do a full refresh of the page
HX-Replace-Url - replaces the current URL in the location bar
HX-Reswap - allows you to specify how the response will be swapped. See hx-swap for possible values
HX-Retarget - a CSS selector that updates the target of the content update to a different element on the page
HX-Reselect - a CSS selector that allows you to choose which part of the response is used to be swapped in. Overrides an existing hx-select on the triggering element
HX-Trigger - allows you to trigger client-side events
HX-Trigger-After-Settle - allows you to trigger client-side events after the settle step
HX-Trigger-After-Swap - allows you to trigger client-side events after the swap step
For more on the HX-Trigger headers, see HX-Trigger Response Headers.




    
Submitting a form via htmx has the benefit of no longer needing the Post/Redirect/Get Pattern.
After successfully processing a POST request on the server, you don’t need to return a HTTP 302 (Redirect). You can directly return the new HTML fragment.
#Request Order of Operations
The order of operations in a htmx request are:
The element is triggered and begins a request
The htmx-request class is applied to the appropriate elements
The request is then issued asynchronously via AJAX
An optional swap delay is applied (see the hx-swap attribute)
The actual content swap is done
the htmx-added class is added to each new piece of content
the htmx-settling class is applied to the target
A settle delay is done (default: 20ms)
The DOM is settled
the htmx-settling class is removed from the target
the htmx-added class is removed from each new piece of content
You can use the htmx-swapping and htmx-settling classes to create
CSS transitions between pages.




    
#Validation
Htmx integrates with the HTML5 Validation API
and will not issue a request for a form if a validatable input is invalid.  This is true for both AJAX requests as well as
WebSocket sends.
Htmx fires events around validation that can be used to hook in custom validation and error handling:
htmx:validation:validate - called before an element’s checkValidity() method is called.  May be used to add in
custom validation logic
htmx:validation:failed - called when checkValidity() returns false, indicating an invalid input
htmx:validation:halted - called when a request is not issued due to validation errors.  Specific errors may be found
in the event.detail.errors object
Non-form elements do not validate before they make requests by default, but you can enable validation by setting
the hx-validate attribute to “true”.




    
#Validation Example
Here is an example of an input that uses the hx-on attribute to catch the
htmx:validation:validate event and require that the input have the value foo:
<form id="example-form" hx-post="/test">
    <input name="example"
           onkeyup="this.setCustomValidity('') // reset the validation on keyup"
           hx-on:htmx:validation:validate="if(this.value != 'foo') {
                    this.setCustomValidity('Please enter the value foo') // set the validation error
                    htmx.find('#example-form').reportValidity()          // report the issue
</form>
Note that all client side validations must be re-done on the server side, as they can always be bypassed.
#Animations
Htmx allows you to use CSS transitions
in many situations using only HTML and CSS.
Please see the Animation Guide for more details on the options available.
#Extensions
Htmx has an extension mechanism that allows you to customize the libraries’ behavior.
Extensions are defined in javascript and then used via
the hx-ext attribute:
<div hx-ext="debug">
    <button hx-post="/example">This button used the debug extension</button>
    <button hx-post="/example" hx-ext="ignore:debug">This button does not</button>
</div>
If you are interested in adding your own extension to htmx, please see the extension docs
#Events & Logging
Htmx has an extensive events mechanism, which doubles as the logging system.
If you want to register for a given htmx event you can use
document.body.addEventListener('htmx:load', function(evt) {
    myJavascriptLib.init(evt.detail.elt);
or, if you would prefer, you can use the following htmx helper:
htmx.on("htmx:load", function(evt) {
    myJavascriptLib.init(evt.detail.elt);
The htmx:load event is fired every time an element is loaded into the DOM by htmx, and is effectively the equivalent
to the normal load event.
Some common uses for htmx events are:
#Initialize A 3rd Party Library With Events
Using the htmx:load event to initialize content is so common that htmx provides a helper function:
htmx.onLoad(function(target) {
    myJavascriptLib.init(target);
This does the same thing as the first example, but is a little cleaner.
#Configure a Request With Events
You can handle the htmx:configRequest event in order to modify an AJAX request before it is issued:
document.body.addEventListener




    
('htmx:configRequest', function(evt) {
    evt.detail.parameters['auth_token'] = getAuthToken(); // add a new parameter into the request
    evt.detail.headers['Authentication-Token'] = getAuthToken(); // add a new header into the request
Here we add a parameter and header to the request before it is sent.
#Modifying Swapping Behavior With Events
You can handle the htmx:beforeSwap event in order to modify the swap behavior of htmx:
document.body.addEventListener('htmx:beforeSwap', function(evt) {
    if(evt.detail.xhr.status === 404){
        // alert the user when a 404 occurs (maybe use a nicer mechanism than alert())
        alert("Error: Could Not Find Resource");
    } else if(evt.detail.xhr.status === 422){
        // allow 422 responses to swap as we are using this as a signal that
        // a form was submitted with bad data and want to rerender with the
        // errors
        // set isError to false to avoid error logging in console
        evt.detail.shouldSwap = true;
        evt.detail.isError = false;
    } else if(evt.detail.xhr.status === 418){
        // if the response code 418 (I'm a teapot) is returned, retarget the
        // content of the response to the element with the id `teapot`
        evt.detail.shouldSwap = true;
        evt.detail.target = htmx.find("#teapot");
Here we handle a few 400-level error response codes
that would normally not do a swap in htmx.
#Event Naming
Note that all events are fired with two different names
Camel Case
Kebab Case
So, for example, you can listen for htmx:afterSwap or for htmx:after-swap.  This facilitates interoperability
with other libraries.  Alpine.js, for example, requires kebab case.
#Logging
If you set a logger at htmx.logger, every event will be logged.  This can be very useful for troubleshooting:
htmx.logger = function(elt, event, data) {
    if(console) {
        console.log(event, elt, data);
#Debugging
Declarative and event driven programming with htmx (or any other declarative language) can be a wonderful and highly productive
activity, but one disadvantage when compared with imperative approaches is that it can be trickier to debug.
Figuring out why something isn’t happening, for example, can be difficult if you don’t know the tricks.
Well, here are the tricks:
The first debugging tool you can use is the htmx.logAll() method.  This will log every event that htmx triggers and
will allow you to see exactly what the library is doing.
htmx.logAll();
Of course, that won’t tell you why htmx isn’t doing something.  You might also not know what events a DOM
element is firing to use as a trigger.  To address this, you can use the
monitorEvents() method available in the
browser console:
monitorEvents(htmx.find("#theElement"));
This will spit out all events that are occurring on the element with the id theElement to the console, and allow you
to see exactly what is going on with it.
Note that this only works from the console, you cannot embed it in a script tag on your page.
Finally, push come shove, you might want to just debug htmx.js by loading up the unminimized version.  It’s
about 2500 lines of javascript, so not an insurmountable amount of code.  You would most likely want to set a break
point in the issueAjaxRequest() and handleAjaxResponse() methods to see what’s going on.
And always feel free to jump on the Discord if you need help.
#Creating Demos
Sometimes, in order to demonstrate a bug or clarify a usage, it is nice to be able to use a javascript snippet
site like jsfiddle.  To facilitate easy demo creation, htmx hosts a demo script
site that will install:
hyperscript
a request mocking library
Simply add the following script tag to your demo/fiddle/whatever:
<script src="https://demo.htmx.org"></script>
This helper allows you to add mock responses by adding template tags with a url attribute to indicate which URL.
The response for that url will be the innerHTML of the template, making it easy to construct mock responses. You can
add a delay to the response with a delay attribute, which should be an integer indicating the number of milliseconds
to delay
You may embed simple expressions in the template with the ${} syntax.
Note that this should only be used for demos and is in no way guaranteed to work for long periods of time
as it will always be grabbing the latest versions htmx and hyperscript!
#Demo Example
Here is an example of the code in action:
<!-- load demo environment -->
<script src="https://demo.htmx.org"></script>
<!-- post to /foo -->
<button hx-post="/foo" hx-target="#result">
    Count Up
</button>
<output id="result"></output>
<!-- respond to /foo with some dynamic content in a template tag -->
<script>
    globalInt = 0;
</script>
<template url="/foo" delay="500"> <!-- note the url and delay attributes -->
    ${globalInt++}
</template>
#Scripting
While htmx encourages a hypermedia approach to building web applications, it offers many options for client scripting. Scripting is included in the REST-ful description of web architecture, see: Code-On-Demand. As much as is feasible, we recommend a hypermedia-friendly approach to scripting in your web application:
Respect HATEOAS
Use events to communicate between components
Use islands to isolate non-hypermedia components from the rest of your application
Consider inline scripting
The primary integration point between htmx and scripting solutions is the events that htmx sends and can
respond to.  See the SortableJS example in the 3rd Party Javascript section for a good template for
integrating a JavaScript library with htmx via events.
Scripting solutions that pair well with htmx include:
VanillaJS - Simply using the built-in abilities of JavaScript to hook in event handlers to
respond to the events htmx emits can work very well for scripting.  This is an extremely lightweight and increasingly
popular approach.
AlpineJS - Alpine.js provides a rich set of tools for creating sophisticated front end scripts,
including reactive programming support, while still remaining extremely lightweight.  Alpine encourages the “inline scripting”
approach that we feel pairs well with htmx.
jQuery - Despite its age and reputation in some circles, jQuery pairs very well with htmx, particularly
in older code-bases that already have a lot of jQuery in them.
hyperscript - Hyperscript is an experimental front-end scripting language created by the same
team that created htmx.  It is designed to embed well in HTML and both respond to and create events, and pairs very well
with htmx.
We have an entire chapter entitled “Client-Side Scripting” in our
book that looks at how scripting can be integrated into your htmx-based application.
#The hx-on* Attributes
HTML allows the embedding of inline scripts via the onevent properties,
such as onClick:
<button onclick="alert('You clicked me!')">
    Click Me!
</button>
This feature allows scripting logic to be co-located with the HTML elements the logic applies to, giving good
Locality of Behaviour (LoB).  Unfortunately, HTML only allows on* attributes for a fixed
number of specific DOM events (e.g. onclick) and
doesn’t provide a generalized mechanism for responding to arbitrary events on elements.
In order to address this shortcoming, htmx offers hx-on* attributes.  These attributes allow
you to respond to any event in a manner that preserves the LoB of the standard on* properties.
If we wanted to respond to the click event using an hx-on attribute, we would write this:
<button hx-on:click="alert('You clicked me!')">
    Click Me!
</button>
So, the string hx-on, followed by a colon (or a dash), then by the name of the event.
For a click event, of course, we would recommend sticking with the standard onclick attribute.  However, consider an
htmx-powered button that wishes to add a parameter to a request using the htmx:config-request event.  This would not
be possible using a standard on* property, but it can be done using the hx-on:htmx:config-request attribute:




    

<button hx-post="/example"
        hx-on:htmx:config-request="event.detail.parameters.example = 'Hello Scripting!'">
    Post Me!
</button>
Here the example parameter is added to the POST request before it is issued, with the value ‘Hello Scripting!’.
The hx-on* attributes are a very simple mechanism for generalized embedded scripting.  It is not a replacement for more
fully developed front-end scripting solutions such as AlpineJS or hyperscript.  It can, however, augment a VanillaJS-based
approach to scripting in your htmx-powered application.
Note that HTML attributes are case insensitive.  This means that, unfortunately, events that rely on capitalization/
camel casing, cannot be responded to.  If you need to support camel case events we recommend using a more fully
functional scripting solution such as AlpineJS or hyperscript.  htmx dispatches all its events in both camelCase and in
kebab-case for this very reason.
#3rd Party Javascript
Htmx integrates fairly well with third party libraries.  If the library fires events on the DOM, you can use those events to
trigger requests from htmx.
A good example of this is the SortableJS demo:
<form class="sortable" hx-post="/items" hx-trigger="end">
    <div class="htmx-indicator">Updating...</div>
    <div><input type='hidden' name='item' value='1'/>Item 1</div>
    <div><input type='hidden' name='item' value='2'/>Item 2</div>
    <div><input type='hidden' name='item' value='2'/>Item 3</div>
</form>
With Sortable, as with most javascript libraries, you need to initialize content at some point.
In jquery you might do this like so:
$(document).ready(function() {
    var sortables = document.body.querySelectorAll(".sortable");
    for (var i = 0; i < sortables.length; i++) {
        var sortable = sortables[i];
        new Sortable(sortable, {
            animation: 150,
            ghostClass: 'blue-background-class'
In htmx, you would instead use the htmx.onLoad function, and you would select only from the newly loaded content,
rather than the entire document:
htmx.onLoad(function(content) {
    var sortables = content.querySelectorAll(".sortable");
    for (var i = 0; i < sortables.length; i++) {
        var sortable = sortables[i];
        new Sortable(sortable, {
            animation: 150,
            ghostClass: 'blue-background-class'
This will ensure that as new content is added to the DOM by htmx, sortable elements are properly initialized.
If javascript adds content to the DOM that has htmx attributes on it, you need to make sure that this content
is initialized with the htmx.process() function.
For example, if you were to fetch some data and put it into a div using the fetch API, and that HTML had
htmx attributes in it, you would need to add a call to htmx.process() like this:
let myDiv = document.getElementById('my-div')
fetch('http://example.com/movies.json')
    .then(response => response.text())
    .then(data => { myDiv.innerHTML = data; htmx.process(myDiv); } );
Some 3rd party libraries create content from HTML template elements. For instance, Alpine JS uses the x-if
attribute on templates to add content conditionally. Such templates are not initially part of the DOM and,
if they contain htmx attributes, will need a call to htmx.process() after they are loaded. The following
example uses Alpine’s $watch function to look for a change of value that would trigger conditional content:
<div x-data="{show_new: false}"
    x-init="$watch('show_new', value => {
        if (show_new) {
            htmx.process(document.querySelector('#new_content'))
    <button @click = "show_new = !show_new">Toggle New Content</button>
    <template x-if="show_new">
        <div id="new_content">
            <a hx-get="/server/newstuff" href="#">New Clickable</a>
        </div>
    </template>
</div>
#Web Components
Please see the Web Components Examples page for examples on how to integrate htmx
with web components.
#Caching
htmx works with standard HTTP caching
mechanisms out of the box.
If your server adds the
Last-Modified
HTTP response header to the response for a given URL, the browser will automatically add the
If-Modified-Since
request HTTP header to the next requests to the same URL. Be mindful that if
your server can render different content for the same URL depending on some other
headers, you need to use the Vary
response HTTP header. For example, if your server renders the full HTML when the
HX-Request header is missing or false, and it renders a fragment of that HTML
when HX-Request: true, you need to add Vary: HX-Request. That causes the cache to be
keyed based on a composite of the response URL and the HX-Request request header —
rather than being based just on the response URL.
If you are unable (or unwilling) to use the Vary header, you can alternatively set the configuration parameter
getCacheBusterParam to true.  If this configuration variable is set, htmx will include a cache-busting parameter
in GET requests that it makes, which will prevent browsers from caching htmx-based and non-htmx based responses
in the same cache slot.
htmx also works with ETag
as expected.  Be mindful that if your server can render different content for the same
URL (for example, depending on the value of the HX-Request header), the server needs
to generate a different ETag for each content.
#Security
htmx allows you to define logic directly in your DOM.  This has a number of advantages, the largest being
Locality of Behavior, which makes your system easier to understand and
maintain.
A concern with this approach, however, is security: since htmx increases the expressiveness of HTML, if a malicious
user is able to inject HTML into your application, they can leverage this expressiveness of htmx to malicious
ends.
#Rule 1: Escape All User Content
The first rule of HTML-based web development has always been: do not trust input from the user.  You should escape all
3rd party, untrusted content that is injected into your site.  This is to prevent, among other issues,
XSS attacks.
There is extensive documentation on XSS and how to prevent it on the excellent OWASP Website,
including a Cross Site Scripting Prevention Cheat Sheet.
The good news is that this is a very old and well understood topic, and the vast majority of server-side templating languages
support automatic escaping of
content to prevent just such an issue.
That being said, there are times people choose to inject HTML more dangerously, often via some sort of raw()
mechanism in their templating language.  This can be done for good reasons, but if the content being injected is coming
from a 3rd party then it must be scrubbed, including removing attributes starting with hx- and data-hx, as well as
inline <script> tags, etc.
If you are injecting raw HTML and doing your own escaping, a best practice is to whitelist the attributes and tags you
allow, rather than to blacklist the ones you disallow.
#htmx Security Tools
Of course, bugs happen and developers are not perfect, so it is good to have a layered approach to security for
your web application, and htmx provides tools to help secure your application as well.
Let’s take a look at them.
#hx-disable
The first tool htmx provides to help further secure your application is the hx-disable
attribute.  This attribute will prevent processing of all htmx attributes on a given element, and on all elements within
it.  So, for example, if you were including raw HTML content in a template (again, this is not recommended!) then you
could place a div around the content with the hx-disable attribute on it:
<div hx-disable>
    <%= raw(user_content) %>
</div>
And htmx will not process any htmx-related attributes or features found in that content.  This attribute cannot be
disabled by injecting further content: if an hx-disable attribute is found anywhere in the parent hierarchy of an
element, it will not be processed by htmx.
#hx-history
Another security consideration is htmx history cache.  You may have pages that have sensitive data that you do not
want stored in the users localStorage cache.  You can omit a given page from the history cache by including the
hx-history attribute anywhere on the page, and setting its value to false.




    

#Configuration Options
htmx also provides configuration options related to security:
htmx.config.selfRequestsOnly - if set to true, only requests to the same domain as the current document will be allowed
htmx.config.allowScriptTags - htmx will process <script> tags found in new content it loads.  If you wish to disable
this behavior you can set this configuration variable to false
htmx.config.historyCacheSize - can be set to 0 to avoid storing any HTML in the localStorage cache
htmx.config.allowEval - can be set to false to disable all features of htmx that rely on eval:
event filters
hx-on: attributes
hx-vals with the js: prefix
hx-headers with the js: prefix
Note that all features removed by disabling eval() can be reimplemented using your own custom javascript and the
htmx event model.
#Events
If you want to allow requests to some domains beyond the current host, but not leave things totally open, you can
use the htmx:validateUrl event.  This event will have the request URL available in the detail.url slot, as well
as a sameHost property.
You can inspect these values and, if the request is not valid, invoke preventDefault() on the event to prevent the
request from being issued.
document.body.addEventListener('htmx:validateUrl', function (evt) {
  // only allow requests to the current server as well as myserver.com
  if (!evt.detail.sameHost && evt.detail.url.hostname !== "myserver.com") {
    evt.preventDefault();
#CSP Options
Browsers also provide tools for further securing your web application.  The most powerful tool available is a
Content Security Policy.  Using a CSP you can tell the
browser to, for example, not issue requests to non-origin hosts, to not evaluate inline script tags, etc.
Here is an example CSP in a meta tag:
    <meta http-equiv="Content-Security-Policy" content="default-src 'self';">
This tells the browser “Only allow connections to the original (source) domain”.  This would be redundant with the
htmx.config.selfRequestsOnly, but a layered approach to security is warranted and, in fact, ideal, when dealing
with application security.
A full discussion of CSPs is beyond the scope of this document, but the MDN Article provide a good jumping off point
for exploring this topic.
#Configuring htmx
Htmx has some configuration options that can be accessed either programmatically or declaratively.  They are
listed below:
Values are gathered for the request
Upon getting a response the target element is marked with the htmx-swapping class
the htmx-swapping class is removed from the target
Header
Description

HX-Boosted
indicates that the request is via an element using hx-boost
HX-Current-URL
the current URL of the browser
HX-History-Restore-Request
“true” if the request is for history restoration after a miss in the local history cache
HX-Prompt
the user response to an hx-prompt
HX-Request
always “true”
HX-Target
the id of the target element if it exists
HX-Trigger-Name
the name of the triggered element if it exists
HX-Trigger
the id of the triggered element if it exists






































You can set them directly in javascript, or you can use a meta tag:
<meta name="htmx-config" content='{"defaultSwapStyle":"outerHTML"}'>
#Conclusion
And that’s it!
Have fun with htmx! You can accomplish quite a bit without writing a lot of code!
Config Variable
Info

htmx.config.historyEnabled
defaults to true, really only useful for testing
htmx.config.historyCacheSize
defaults to 10
htmx.config.refreshOnHistoryMiss
defaults to false, if set to true htmx will issue a full page refresh on history misses rather than use an AJAX request
htmx.config.defaultSwapStyle
defaults to innerHTML
htmx.config.defaultSwapDelay
defaults to 0
htmx.config.defaultSettleDelay
defaults to 20
htmx.config.includeIndicatorStyles
defaults to true (determines if the indicator styles are loaded)
htmx.config.indicatorClass
defaults to htmx-indicator
htmx.config.requestClass
defaults to htmx-request
htmx.config.addedClass
defaults to htmx-added
htmx.config.settlingClass
defaults to htmx-settling
htmx.config.swappingClass
defaults to htmx-swapping
htmx.config.allowEval
defaults to true, can be used to disable htmx’s use of eval for certain features (e.g. trigger filters)
htmx.config.allowScriptTags
defaults to true, determines if htmx will process script tags found in new content
htmx.config.inlineScriptNonce
defaults to '', meaning that no nonce will be added to inline scripts
htmx.config.attributesToSettle
defaults to ["class", "style", "width", "height"], the attributes to settle during the settling phase
htmx.config.inlineStyleNonce
defaults to '', meaning that no nonce will be added to inline styles
htmx.config.useTemplateFragments
defaults to false, HTML template tags for parsing content from the server (not IE11 compatible!)
htmx.config.wsReconnectDelay
defaults to full-jitter
htmx.config.wsBinaryType
defaults to blob, the type of binary data being received over the WebSocket connection
htmx.config.disableSelector
defaults to [hx-disable], [data-hx-disable], htmx will not process elements with this attribute on it or a parent
htmx.config.withCredentials
defaults to false, allow cross-site Access-Control requests using credentials such as cookies, authorization headers or TLS client certificates
htmx.config.timeout
defaults to 0, the number of milliseconds a request can take before automatically being terminated
htmx.config.scrollBehavior
defaults to ‘smooth’, the behavior for a boosted link on page transitions. The allowed values are auto and smooth. Smooth will smoothscroll to the top of the page while auto will behave like a vanilla link.
htmx.config.defaultFocusScroll
if the focused element should be scrolled into view, defaults to false and can be overridden using the focus-scroll swap modifier.
htmx.config.getCacheBusterParam
defaults to false, if set to true htmx will append the target element to the GET request in the format org.htmx.cache-buster=targetElementId
htmx.config.globalViewTransitions
if set to true, htmx will use the View Transition API when swapping in new content.
htmx.config.methodsThatUseUrlParams
defaults to ["get"], htmx will format requests with these methods by encoding their parameters in the URL, not the request body
htmx.config.selfRequestsOnly
defaults to true, whether to only allow AJAX requests to the same domain as the current document
htmx.config.ignoreTitle
defaults to false, if set to true htmx will not update the title of the document when a title tag is found in new content
htmx.config.disableInheritance
disables attribute inheritance in htmx, which can then be overridden by the hx-inherit attribute
htmx.config.scrollIntoViewOnBoost
defaults to true, whether or not the target of a boosted element is scrolled into the viewport. If hx-target is omitted on a boosted element, the target defaults to body, causing the page to scroll to the top.
htmx.config.triggerSpecsCache
defaults to null, the cache to store evaluated trigger specifications into, improving parsing performance at the cost of more memory usage. You may define a simple object to use a never-clearing cache, or implement your own system using a proxy object
htmx.config.allowNestedOobSwaps
defaults to true, whether to process OOB swaps on elements that are nested within the main response element. See Nested OOB Swaps.