HTML: The Living Standard

Edition for Web Developers — Last Updated 17 April 2025

1. 1. 4.11 Interactive elements
      1. 4.11.1 The details element
      2. 4.11.2 The summary element
      3. 4.11.3 Commands
         1. 4.11.3.1 Facets
      4. 4.11.4 The dialog element
      5. 4.11.5 Dialog light dismiss

4.11 Interactive elements

4.11.1 The details element

Categories:

Flow content.

Interactive content.

Palpable content.

Contexts in which this element can be used:

Where flow content is expected.

Content model:

One summary element followed by flow content.

Tag omission in text/html:

Neither tag is omissible.

Content attributes:

Global attributes

name — Name of group of mutually-exclusive details elements

open — Whether the details are visible

Accessibility considerations:

For authors.

For implementers.

DOM interface:

Uses HTMLDetailsElement.

The details element represents a disclosure widget from which the user can obtain additional information or controls.

As with all HTML elements, it is not conforming to use the details element when attempting to represent another type of control. For example, tab widgets and menu widgets are not disclosure widgets, so abusing the details element to implement these patterns is incorrect.

The details element is not appropriate for footnotes. Please see the section on footnotes for details on how to mark up footnotes.

The summary element child of the element, if any, represents the summary or legend of the details.

The rest of the element's contents represents the additional information or controls.

The name content attribute gives the name of the group of related details elements that the element is a member of. Opening one member of this group causes other members of the group to close. If the attribute is specified, its value must not be the empty string.

Before using this feature, authors should consider whether this grouping of related details elements into an exclusive accordion is helpful or harmful to users. While using an exclusive accordion can reduce the maximum amount of space that a set of content can occupy, it can also frustrate users who have to open many items to find what they want or users who want to look at the contents of multiple items at the same time.

A document must not contain more than one details element in the same details name group that has the open attribute present. Authors must not use script to add details elements to a document in a way that would cause a details name group to have more than one details element with the open attribute present.

The group of elements that is created by a common name attribute is exclusive, meaning that at most one of the details elements can be open at once. While this exclusivity is enforced by user agents, the resulting enforcement immediately changes the open attributes in the markup. This requirement on authors forbids such misleading markup.

A document must not contain a details element that is a descendant of another details element in the same details name group.

Documents that use the name attribute to group multiple related details elements should keep those related elements together in a containing element (such as a section element or article element). When it makes sense for the group to be introduced with a heading, authors should put that heading in a heading element at the start of the containing element.

Visually and programmatically grouping related elements together can be important for accessible user experiences. This can help users understand the relationship between such elements. When related elements are in disparate sections of a web page rather than being grouped, the elements' relationships to each other can be less discoverable or understandable.

The open content attribute is a boolean attribute. If present, it indicates that both the summary and the additional information is to be shown to the user. If the attribute is absent, only the summary is to be shown.

The ancestor details revealing algorithm is to run the following steps on currentNode:

1. While currentNode has a parent node within the flat tree:

   1. If currentNode is slotted into the second slot of a details element:

      1. Set currentNode to the details element which currentNode is slotted into.

      2. If the open attribute is not set on currentNode, then set the open attribute on currentNode to the empty string.

   2. Otherwise, set currentNode to the parent node of currentNode within the flat tree.

<section class="progress window">
 <h1>Copying "Really Achieving Your Childhood Dreams"</h1>
 <details>
  <summary>Copying... <progress max="375505392" value="97543282"></progress> 25%</summary>
  <dl>
   <dt>Transfer rate:</dt> <dd>452KB/s</dd>
   <dt>Local filename:</dt> <dd>/home/rpausch/raycd.m4v</dd>
   <dt>Remote filename:</dt> <dd>/var/www/lectures/raycd.m4v</dd>
   <dt>Duration:</dt> <dd>01:16:27</dd>
   <dt>Color profile:</dt> <dd>SD (6-1-6)</dd>
   <dt>Dimensions:</dt> <dd>320×240</dd>
  </dl>
 </details>
</section>

<details>
 <summary><label for=fn>Name & Extension:</label></summary>
 <p><input type=text id=fn name=fn value="Pillar Magazine.pdf">
 <p><label><input type=checkbox name=ext checked> Hide extension</label>
</details>

<section class="characteristics">
 <details name="frame-characteristics">
  <summary>Material</summary>
  The picture frame is made of solid oak wood.
 </details>
 <details name="frame-characteristics">
  <summary>Size</summary>
  The picture frame fits a photo 40cm tall and 30cm wide.
  The frame is 45cm tall, 35cm wide, and 2cm thick.
 </details>
 <details name="frame-characteristics">
  <summary>Color</summary>
  The picture frame is available in its natural wood
  color, or with black stain.
 </details>
</section>

<section class="characteristics">
 <details name="frame-characteristics" id="d1" open>...</details>
 <details name="frame-characteristics" id="d2">...</details>
 <details name="frame-characteristics" id="d3">...</details>
</section>

document.getElementById("d2").setAttribute("open", "");

<section class="characteristics">
 <details name="frame-characteristics" id="d1">...</details>
 <details name="frame-characteristics" id="d2" open>...</details>
 <details name="frame-characteristics" id="d3">...</details>
</section>

<style>
 details > summary { transition: color 1s; color: black; }
 details[open] > summary { color: red; }
</style>
<details>
 <summary>Automated Status: Operational</summary>
 <p>Velocity: 12m/s</p>
 <p>Direction: North</p>
</details>

4.11.2 The summary element

Categories:

None.

Contexts in which this element can be used:

As the first child of a details element.

Content model:

Phrasing content, optionally intermixed with heading content.

Tag omission in text/html:

Neither tag is omissible.

Content attributes:

Global attributes

Accessibility considerations:

For authors.

For implementers.

DOM interface:

Uses HTMLElement.

The summary element represents a summary, caption, or legend for the rest of the contents of the summary element's parent details element.

4.11.3 Commands

4.11.3.1 Facets

A command is the abstraction behind menu items, buttons, and links. Once a command is defined, other parts of the interface can refer to the same command, allowing many access points to a single feature to share facets such as the Disabled State.

Commands are defined to have the following facets:

Label

The name of the command as seen by the user.

Access Key

A key combination selected by the user agent that triggers the command. A command might not have an Access Key.

Hidden State

Whether the command is hidden or not (basically, whether it should be shown in menus).

Disabled State

Whether the command is relevant and can be triggered or not.

Action

The actual effect that triggering the command will have. This could be a scripted event handler, a URL to which to navigate, or a form submission.

User agents may expose the commands that match the following criteria:

• The Hidden State facet is false (visible)

• The element is in a document with a non-null browsing context.

• Neither the element nor any of its ancestors has a hidden attribute specified.

User agents are encouraged to do this especially for commands that have Access Keys, as a way to advertise those keys to the user.

For example, such commands could be listed in the user agent's menu bar.

4.11.4 The dialog element

Categories:

Flow content.

Contexts in which this element can be used:

Where flow content is expected.

Content model:

Flow content.

Tag omission in text/html:

Neither tag is omissible.

Content attributes:

Global attributes

closedby — Which user actions will close the dialog

open — Whether the dialog box is showing

Accessibility considerations:

For authors.

For implementers.

DOM interface:

Uses HTMLDialogElement.

The dialog element represents a transitory part of an application, in the form of a small window ("dialog box"), which the user interacts with to perform a task or gather information. Once the user is done, the dialog can be automatically closed by the application, or manually closed by the user.

Especially for modal dialogs, which are a familiar pattern across all types of applications, authors should work to ensure that dialogs in their web applications behave in a way that is familiar to users of non-web applications.

As with all HTML elements, it is not conforming to use the dialog element when attempting to represent another type of control. For example, context menus, tooltips, and popup listboxes are not dialog boxes, so abusing the dialog element to implement these patterns is incorrect.

An important part of user-facing dialog behavior is the placement of initial focus. The dialog focusing steps attempt to pick a good candidate for initial focus when a dialog is shown, but might not be a substitute for authors carefully thinking through the correct choice to match user expectations for a specific dialog. As such, authors should use the autofocus attribute on the descendant element of the dialog that the user is expected to immediately interact with after the dialog opens. If there is no such element, then authors should use the autofocus attribute on the dialog element itself.

<dialog>
  <label>Product Number <input type="text" readonly></label>
  <label>Product Name <input type="text" autofocus></label>
</dialog>

Another important aspect of user behavior is whether dialogs are scrollable or not. In some cases, overflow (and thus scrollability) cannot be avoided, e.g., when it is caused by the user's high text zoom settings. But in general, scrollable dialogs are not expected by users. Adding large text nodes directly to dialog elements is particularly bad as this is likely to cause the dialog element itself to overflow. Authors are best off avoiding them.

<dialog style="height: 80vh;">
  <div style="overflow: auto; height: 60vh;" autofocus>
    <p>By placing an order via this Web site on the first day of the fourth month of the year
    2010 Anno Domini, you agree to grant Us a non-transferable option to claim, for now and for
    ever more, your immortal soul.</p>
    <p>Should We wish to exercise this option, you agree to surrender your immortal soul,
    and any claim you may have on it, within 5 (five) working days of receiving written
    notification from  this site or one of its duly authorized minions.</p>
    <!-- ... etc., with many more <p> elements ... -->
  </div>
  <form method="dialog">
    <button type="submit" value="agree">Agree</button>
    <button type="submit" value="disagree">Disagree</button>
  </form>
</dialog>

<dialog>
 <h1>Add to Wallet</h1>
 <p><strong><label for=amt>How many gold coins do you want to add to your wallet?</label></strong></p>
 <p><input id=amt name=amt type=number min=0 step=0.01 value=100></p>
 <p><small>You add coins at your own risk.</small></p>
 <p><label><input name=round type=checkbox> Only add perfectly round coins</label></p>
 <p><input type=button onclick="submit()" value="Add Coins"></p>
</dialog>

The open attribute is a boolean attribute. When specified, it indicates that the dialog element is active and that the user can interact with it.

The closedby content attribute is an enumerated attribute with the following keywords and states:

The closedby attribute's invalid value default and missing value default are both the Auto state.

The Auto state behaves as Close Request state when the dialog was shown using its showModal() method; otherwise the None state.

The tabindex attribute must not be specified on dialog elements.

dialog.show()

Displays the dialog element.

dialog.showModal()

Displays the dialog element and makes it the top-most modal dialog.

This method honors the autofocus attribute.

dialog.close([ result ])

Closes the dialog element.

The argument, if provided, provides a return value.

dialog.requestClose([ result ])

Acts as if a close request was sent targeting dialog, by first firing a cancel event, and if that event is not canceled with preventDefault(), proceeding to close the dialog in the same way as the close() method (including firing a close event).

This is a helper utility that can be used to consolidate cancelation and closing logic into the cancel and close event handlers, by having all non-close request closing affordances call this method.

Note that this method ignores the closedby attribute: that is, even if closedby is set to "none", the same behavior will apply.

The argument, if provided, provides a return value.

dialog.returnValue [ = result ]

Returns the dialog's return value.

Can be set, to update the return value.

To queue a dialog toggle event task given a dialog element element, a string oldState, and a string newState:

1. If element's dialog toggle task tracker is not null, then:

   1. Set oldState to element's dialog toggle task tracker's old state.

   2. Remove element's dialog toggle task tracker's task from its task queue.

   3. Set element's dialog toggle task tracker to null.

2. Queue an element task given the DOM manipulation task source and element to run the following steps:

   1. Fire an event named toggle at element, using ToggleEvent, with the oldState attribute initialized to oldState and the newState attribute initialized to newState.

   2. Set element's dialog toggle task tracker to null.

3. Set element's dialog toggle task tracker to a struct with task set to the just-queued task and old state set to oldState.

To retrieve a dialog's computed closed-by state, given a dialog dialog:

1. If the state of dialog's closedby attribute is Auto:

   1. If dialog's is modal is true, then return Close Request.

   2. Return None.

2. Return the state of dialog's closedby attribute.

The dialog focusing steps, given a dialog element subject, are as follows:

1. If the allow focus steps given subject's node document return false, then return.

2. Let control be null.

3. If subject has the autofocus attribute, then set control to subject.

4. If control is null, then set control to the focus delegate of subject.

5. If control is null, then set control to subject.

6. Run the focusing steps for control.

   If control is not focusable, this will do nothing. This would only happen if subject had no focus delegate, and the user agent decided that dialog elements were not generally focusable. In that case, any earlier modifications to the focused area of the document will apply.

7. Let topDocument be control's node navigable's top-level traversable's active document.

8. If control's node document's origin is not the same as the origin of topDocument, then return.

9. Empty topDocument's autofocus candidates.

10. Set topDocument's autofocus processed flag to true.

4.11.5 Dialog light dismiss

"Light dismiss" means that clicking outside of a dialog element whose closedby attribute is in the Any state will close the dialog element. This is in addition to how such dialogs respond to close requests.

To light dismiss open dialogs, given a PointerEvent event:

1. Assert: event's isTrusted attribute is true.

2. Let document be event's target's node document.

3. If document's open dialogs list is empty, then return.

4. Let ancestor be the result of running nearest clicked dialog given event.

5. If event's type is "pointerdown", then set document's dialog pointerdown target to ancestor.

6. If event's type is "pointerup", then:

   1. Let sameTarget be true if ancestor is document's dialog pointerdown target.

   2. Set document's dialog pointerdown target to null.

   3. If sameTarget is false, then return.

   4. Let topmostDialog be the last element of document's open dialogs list.

   5. If ancestor is topmostDialog, then return.

   6. If topmostDialog's computed closed-by state is not Any, then return.

   7. Assert: topmostDialog's close watcher is not null.

   8. Request to close topmostDialog's close watcher with false.

To run light dismiss activities, given a PointerEvent event:

1. Run light dismiss open popovers with event.

2. Run light dismiss open dialogs with event.

Run light dismiss activities will be called by the Pointer Events spec when the user clicks or touches anywhere on the page.

To find the nearest clicked dialog, given a PointerEvent event:

1. Let target be event's target.

2. If target is a dialog element, target has an open attribute, target's is modal is true, and event's clientX and clientY are outside the bounds of target, then return null.

   The check for clientX and clientY is because a pointer event that hits the ::backdrop pseudo element of a dialog will result in event having a target of the dialog element itself.

3. Let currentNode be target.

4. While currentNode is not null:

   1. If currentNode is a dialog element and currentNode has an open attribute, then return currentNode.

   2. Set currentNode to currentNode's parent in the flat tree.

5. Return null.