+++
title = "Reference"
+++

## Contents

* [htmx Core Attributes](#attributes)
* [htmx Additional Attributes](#attributes-additional)
* [htmx CSS Classes](#classes)
* [htmx Request Headers](#request_headers)
* [htmx Response Headers](#response_headers)
* [htmx Events](#events)
* [htmx Extensions](/extensions#included)
* [JavaScript API](#api)

## Core Attribute Reference {#attributes}

The following are the most common attributes when using htmx.

<div class="info-table">

| Attribute                                          | Description |
|----------------------------------------------------|-------------|
| [`hx-boost`](@/attributes/hx-boost.md)             | add or remove [progressive enhancement](https://en.wikipedia.org/wiki/Progressive_enhancement) for links and forms
| [`hx-get`](@/attributes/hx-get.md)                 | issues a `GET` to the specified URL
| [`hx-post`](@/attributes/hx-post.md)               | issues a `POST` to the specified URL
| [`hx-on`](@/attributes/hx-on.md)                   | handle any event with a script inline
| [`hx-push-url`](@/attributes/hx-push-url.md)       | pushes the URL into the browser location bar, creating a new history entry
| [`hx-select`](@/attributes/hx-select.md)           | select content to swap in from a response
| [`hx-select-oob`](@/attributes/hx-select-oob.md)   | select content to swap in from a response, out of band (somewhere other than the target)
| [`hx-swap`](@/attributes/hx-swap.md)               | controls how content is swapped in (`outerHTML`, `beforeend`, `afterend`, ...)
| [`hx-swap-oob`](@/attributes/hx-swap-oob.md)       | marks content in a response to be out of band (should swap in somewhere other than the target)
| [`hx-target`](@/attributes/hx-target.md)           | specifies the target element to be swapped
| [`hx-trigger`](@/attributes/hx-trigger.md)         | specifies the event that triggers the request
| [`hx-vals`](@/attributes/hx-vals.md)               | adds values to the parameters to submit with the request (JSON-formatted)

</div>

## Additional Attribute Reference {#attributes-additional}

The table below lists all other attributes available in htmx.

<div class="info-table">

| Attribute                                          | Description |
|----------------------------------------------------|-------------|
| [`hx-confirm`](@/attributes/hx-confirm.md)         | shows a `confirm()` dialog before issuing a request
| [`hx-delete`](@/attributes/hx-delete.md)           | issues a `DELETE` to the specified URL
| [`hx-disable`](@/attributes/hx-disable.md)         | disables htmx processing for the given node and any children nodes
| [`hx-disinherit`](@/attributes/hx-disinherit.md)   | control and disable automatic attribute inheritance for child nodes
| [`hx-encoding`](@/attributes/hx-encoding.md)       | changes the request encoding type
| [`hx-ext`](@/attributes/hx-ext.md)                 | extensions to use for this element
| [`hx-headers`](@/attributes/hx-headers.md)         | adds to the headers that will be submitted with the request
| [`hx-history`](@/attributes/hx-history.md)         | prevent sensitive data being saved to the history cache
| [`hx-history-elt`](@/attributes/hx-history-elt.md) | the element to snapshot and restore during history navigation
| [`hx-include`](@/attributes/hx-include.md)         | include additional data in requests
| [`hx-indicator`](@/attributes/hx-indicator.md)     | the element to put the `htmx-request` class on during the request
| [`hx-params`](@/attributes/hx-params.md)           | filters the parameters that will be submitted with a request
| [`hx-patch`](@/attributes/hx-patch.md)             | issues a `PATCH` to the specified URL
| [`hx-preserve`](@/attributes/hx-preserve.md)       | specifies elements to keep unchanged between requests
| [`hx-prompt`](@/attributes/hx-prompt.md)           | shows a `prompt()` before submitting a request
| [`hx-put`](@/attributes/hx-put.md)                 | issues a `PUT` to the specified URL
| [`hx-replace-url`](@/attributes/hx-replace-url.md) | replace the URL in the browser location bar
| [`hx-request`](@/attributes/hx-request.md)         | configures various aspects of the request
| [`hx-sse`](@/extensions/server-sent-events.md)     | has been moved to an extension.  [Documentation for older versions](@/attributes/hx-sse.md)
| [`hx-sync`](@/attributes/hx-sync.md)               | control how requests made by different elements are synchronized
| [`hx-validate`](@/attributes/hx-validate.md)       | force elements to validate themselves before a request
| [`hx-vars`](@/attributes/hx-vars.md)               | adds values dynamically to the parameters to submit with the request (deprecated, please use [`hx-vals`](@/attributes/hx-vals.md))
| [`hx-ws`](@/extensions/web-sockets.md)             | has been moved to an extension.  [Documentation for older versions](@/attributes/hx-ws.md)


</div>

## CSS Class Reference {#classes}

<div class="info-table">

| Class | Description |
|-----------|-------------|
| `htmx-added` | Applied to a new piece of content before it is swapped, removed after it is settled.
| `htmx-indicator` | A dynamically generated class that will toggle visible (opacity:1) when a `htmx-request` class is present
| `htmx-request` | Applied to either the element or the element specified with [`hx-indicator`](@/attributes/hx-indicator.md) while a request is ongoing
| `htmx-settling` | Applied to a target after content is swapped, removed after it is settled. The duration can be modified via [`hx-swap`](@/attributes/hx-swap.md).
| `htmx-swapping` | Applied to a target before any content is swapped, removed after it is swapped. The duration can be modified via [`hx-swap`](@/attributes/hx-swap.md).

</div>

## HTTP Header Reference {#headers}

### Request Headers Reference {#request_headers}

<div class="info-table">

| Header | Description |
|-------|-------------|
| `HX-Boosted` | indicates that the request is via an element using [hx-boost](@/attributes/hx-boost.md)
| `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](@/attributes/hx-prompt.md)
| `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

</div>

### Response Headers Reference {#response_headers}

<div class="info-table">

| Header                                               | Description |
|------------------------------------------------------|-------------|
| [`HX-Location`](@/headers/hx-location.md)            | Allows you to do a client-side redirect that does not do a full page reload
| [`HX-Push-Url`](@/headers/hx-push-url.md)            | 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 a full refresh of the page
| [`HX-Replace-Url`](@/headers/hx-replace-url.md)      | replaces the current URL in the location bar
| `HX-Reswap`                                          | Allows you to specify how the response will be swapped. See [hx-swap](@/attributes/hx-swap.md) 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`](@/attributes/hx-select.md) on the triggering element
| [`HX-Trigger`](@/headers/hx-trigger.md)              | allows you to trigger client side events, see the [documentation](@/headers/hx-trigger.md) for more info
| [`HX-Trigger-After-Settle`](@/headers/hx-trigger.md) | allows you to trigger client side events, see the [documentation](@/headers/hx-trigger.md) for more info
| [`HX-Trigger-After-Swap`](@/headers/hx-trigger.md)   | allows you to trigger client side events, see the [documentation](@/headers/hx-trigger.md) for more info

</div>

## Event Reference {#events}

<div class="info-table">

| Event | Description |
|-------|-------------|
| [`htmx:abort`](@/events.md#htmx:abort) | send this event to an element to abort a request
| [`htmx:afterOnLoad`](@/events.md#htmx:afterOnLoad) | triggered after an AJAX request has completed processing a successful response
| [`htmx:afterProcessNode`](@/events.md#htmx:afterProcessNode) | triggered after htmx has initialized a node
| [`htmx:afterRequest`](@/events.md#htmx:afterRequest)  | triggered after an AJAX request has completed
| [`htmx:afterSettle`](@/events.md#htmx:afterSettle)  | triggered after the DOM has settled
| [`htmx:afterSwap`](@/events.md#htmx:afterSwap)  | triggered after new content has been swapped in
| [`htmx:beforeOnLoad`](@/events.md#htmx:beforeOnLoad)  | triggered before any response processing occurs
| [`htmx:beforeProcessNode`](@/events.md#htmx:afterProcessNode) | triggered before htmx initializes a node
| [`htmx:beforeRequest`](@/events.md#htmx:beforeRequest)  | triggered before an AJAX request is made
| [`htmx:beforeSwap`](@/events.md#htmx:beforeSwap)  | triggered before a swap is done, allows you to configure the swap
| [`htmx:beforeSend`](@/events.md#htmx:beforeSend)  | triggered just before an ajax request is sent
| [`htmx:configRequest`](@/events.md#htmx:configRequest)  | triggered before the request, allows you to customize parameters, headers
| [`htmx:confirm`](@/events.md#htmx:confirm)  | triggered after a trigger occurs on an element, allows you to cancel (or delay) issuing the AJAX request
| [`htmx:historyCacheError`](@/events.md#htmx:historyCacheError)  | triggered on an error during cache writing
| [`htmx:historyCacheMiss`](@/events.md#htmx:historyCacheMiss)  | triggered on a cache miss in the history subsystem
| [`htmx:historyCacheMissError`](@/events.md#htmx:historyCacheMissError)  | triggered on a unsuccessful remote retrieval
| [`htmx:historyCacheMissLoad`](@/events.md#htmx:historyCacheMissLoad)  | triggered on a successful remote retrieval
| [`htmx:historyRestore`](@/events.md#htmx:historyRestore)  | triggered when htmx handles a history restoration action
| [`htmx:beforeHistorySave`](@/events.md#htmx:beforeHistorySave)  | triggered before content is saved to the history cache
| [`htmx:load`](@/events.md#htmx:load)  | triggered when new content is added to the DOM
| [`htmx:noSSESourceError`](@/events.md#htmx:noSSESourceError)  | triggered when an element refers to a SSE event in its trigger, but no parent SSE source has been defined
| [`htmx:onLoadError`](@/events.md#htmx:onLoadError)  | triggered when an exception occurs during the onLoad handling in htmx
| [`htmx:oobAfterSwap`](@/events.md#htmx:oobAfterSwap)  | triggered after an out of band element as been swapped in
| [`htmx:oobBeforeSwap`](@/events.md#htmx:oobBeforeSwap)  | triggered before an out of band element swap is done, allows you to configure the swap
| [`htmx:oobErrorNoTarget`](@/events.md#htmx:oobErrorNoTarget)  | triggered when an out of band element does not have a matching ID in the current DOM
| [`htmx:prompt`](@/events.md#htmx:prompt)  | triggered after a prompt is shown
| [`htmx:pushedIntoHistory`](@/events.md#htmx:pushedIntoHistory)  | triggered after an url is pushed into history
| [`htmx:responseError`](@/events.md#htmx:responseError)  | triggered when an HTTP response error (non-`200` or `300` response code) occurs
| [`htmx:sendError`](@/events.md#htmx:sendError)  | triggered when a network error prevents an HTTP request from happening
| [`htmx:sseError`](@/events.md#htmx:sseError)  | triggered when an error occurs with a SSE source
| [`htmx:sseOpen`](/events#htmx:sseOpen)  | triggered when a SSE source is opened
| [`htmx:swapError`](@/events.md#htmx:swapError)  | triggered when an error occurs during the swap phase
| [`htmx:targetError`](@/events.md#htmx:targetError)  | triggered when an invalid target is specified
| [`htmx:timeout`](@/events.md#htmx:timeout)  | triggered when a request timeout occurs
| [`htmx:validation:validate`](@/events.md#htmx:validation:validate)  | triggered before an element is validated
| [`htmx:validation:failed`](@/events.md#htmx:validation:failed)  | triggered when an element fails validation
| [`htmx:validation:halted`](@/events.md#htmx:validation:halted)  | triggered when a request is halted due to validation errors
| [`htmx:xhr:abort`](@/events.md#htmx:xhr:abort)  | triggered when an ajax request aborts
| [`htmx:xhr:loadend`](@/events.md#htmx:xhr:loadend)  | triggered when an ajax request ends
| [`htmx:xhr:loadstart`](@/events.md#htmx:xhr:loadstart)  | triggered when an ajax request starts
| [`htmx:xhr:progress`](@/events.md#htmx:xhr:progress)  | triggered periodically during an ajax request that supports progress events

</div>

## JavaScript API Reference {#api}

<div class="info-table">

| Method | Description |
|-------|-------------|
| [`htmx.addClass()`](@/api.md#addClass)  | Adds a class to the given element
| [`htmx.ajax()`](@/api.md#ajax)  | Issues an htmx-style ajax request
| [`htmx.closest()`](@/api.md#closest)  | Finds the closest parent to the given element matching the selector
| [`htmx.config`](@/api.md#config)  | A property that holds the current htmx config object
| [`htmx.createEventSource`](@/api.md#createEventSource)  | A property holding the function to create SSE EventSource objects for htmx
| [`htmx.createWebSocket`](@/api.md#createWebSocket)  | A property holding the function to create WebSocket objects for htmx
| [`htmx.defineExtension()`](@/api.md#defineExtension)  | Defines an htmx [extension](@/extensions/_index.md)
| [`htmx.find()`](@/api.md#find)  | Finds a single element matching the selector
| [`htmx.findAll()` `htmx.findAll(elt, selector)`](@/api.md#find)  | Finds all elements matching a given selector
| [`htmx.logAll()`](@/api.md#logAll)  | Installs a logger that will log all htmx events
| [`htmx.logger`](@/api.md#logger)  | A property set to the current logger (default is `null`)
| [`htmx.off()`](@/api.md#off)  | Removes an event listener from the given element
| [`htmx.on()`](@/api.md#on)  | Creates an event listener on the given element, returning it
| [`htmx.onLoad()`](@/api.md#onLoad)  | Adds a callback handler for the `htmx:load` event
| [`htmx.parseInterval()`](@/api.md#parseInterval)  | Parses an interval declaration into a millisecond value
| [`htmx.process()`](@/api.md#process)  | Processes the given element and its children, hooking up any htmx behavior
| [`htmx.remove()`](@/api.md#remove)  | Removes the given element
| [`htmx.removeClass()`](@/api.md#removeClass)  | Removes a class from the given element
| [`htmx.removeExtension()`](@/api.md#removeExtension)  | Removes an htmx [extension](@/extensions/_index.md)
| [`htmx.takeClass()`](@/api.md#takeClass)  | Takes a class from other elements for the given element
| [`htmx.toggleClass()`](@/api.md#toggleClass)  | Toggles a class from the given element
| [`htmx.trigger()`](@/api.md#trigger)  | Triggers an event on an element
| [`htmx.values()`](@/api.md#values)  | Returns the input values associated with the given element

</div>