HTML <summary> Tag

The HTML <summary> tag specifies a summary/legend that can be used in conjunction with the <details> tag. This summary/legend can be clicked on to expand/collapse the details as required.

Although the <summary> tag is not mandatory, it is useful when working with multiple <details> elements, because each <summary> can provide an informative legend that distinguishes each <details> element from the others.


The <summary> tag is written as <summary></summary> with the summary/legend inserted between the start and end tags.

The <summary> element must be the first child of a <details> tag. The expandable/collapsible content directly follows the <summary> tag (but is also contained within the <details> element).

Like this:


Basic tag usage

Here, the <summary> is used along with the <details> tag to create expandable content.

Default Legend

The <summary> is not mandatory when using the <details> tag. If you leave the <summary> tag out, the browser should create its own legend (however, this is not ideal if you have multiple <details> elements).

Multiple <summary> Elements

You can have multiple <details> elements, all expanding and collapsing their own content. This is where the <summary> tag can really come in handy, otherwise you will see a whole bunch of headings that read Details with nothing else to distinguish each one.

Styling the <summary> Element

You can use CSS to add styles to the <summary> element. Not only that, you can use it to style the element while the <details> element is in its various states (i.e. open and closed). In other words, you can specify different styles to use on both the <summary> and the <details> elements based on whether the user has expanded or collapsed the control.

Like this:


Attributes can be added to an HTML element to provide more information about how the element should appear or behave.

There are 3 kinds of attributes that you can add to your HTML tags: Element-specific, global, and event handler content attributes.

The <summary> element accepts the following attributes.

Element-Specific Attributes

This table shows the attributes that are specific to the <summary> tag/element.


Global Attributes

The following attributes are standard across all HTML5 elements. Therefore, you can use these attributes with the <summary> tag , as well as with all other HTML tags.

For a full explanation of these attributes, see HTML 5 global attributes.

Event Handler Content Attributes

Event handler content attributes enable you to invoke a script from within your HTML. The script is invoked when a certain "event" occurs. Each event handler content attribute deals with a different event.

Below are the standard HTML5 event handler content attributes.

Again, you can use any of these with the <summary> element, as well as any other HTML5 element.

For a full explanation of these attributes, see HTML 5 event handler content attributes.

Differences Between HTML 4 & HTML 5

The <summary> element was not part of HTML 4 and earlier specifications.

The <details> tag was also not introduced as part of the HTML5 specification. It was introduced in the HTML 5.1 specification, as well as the WHATWG HTML Living Standard.

For more detail on the <summary> element, see HTML5 <summary> Tag. Also check out the links to the official specifications below.


Here's a template for the <summary> tag with all available attributes for the tag (based on HTML5). These are grouped into attribute types, each type separated by a space. In many cases, you will probably only need one or two (if any) attributes. Simply remove the attributes you don't need.

Note that the <summary> element does not actually have any local attributes (i.e. attributes that are specific to the element), but the following global attributes and event handlers are available to the element (and all other HTML elements).

For more information on attributes for this tag, see HTML5 <summary> Tag.

Tag Details

For more details about the <summary> tag, see HTML5 <summary> Tag.


Here are the official specifications for the <summary> element.

What's the Difference?

W3C creates "snapshot" specifications that don't change once defined. So the HTML5 specification won't change once it becomes an official recommendation. WHATWG on the other hand, develops a "living standard" that is updated on a regular basis. In general, you will probably find that the HTML living standard will be more closely aligned to the current W3C draft than to the HTML5 specification.