Focus

Interactive elements, including form controls, links, and buttons, are by default focusable and tabbable. Tabbable elements are part of the document's sequential focus navigation order. Other elements are inert, meaning they are not interactive. With HTML attributes, it's possible to make interactive elements inert and to make inert elements interactive.

By default, the navigation focus order is the same as the visual order, which is the source code order. There are HTML attributes that can alter this order and CSS properties that can alter the visual order of content. Changing the tabbing order with HTML or visual rendering order with CSS can harm user experience.

Don't alter the perceived and actual tabbing order with CSS and HTML. As the following two examples demonstrate, tab orders that differ from the visually expected order are confusing to users and bad for user experience.

In this example, the value of the tabindex attribute has made the tab order chaotic:

In this example, CSS has created a divergence between the tabbing order and the visual order of the content:

The flex-flow: row-reverse; declaration has reversed the visual order. In addition, the CSS order property was applied to the sixth word, "This", which visually moved that one word. The tabbing sequence is the order of the code, which no longer matches the visual order, creating a disconnect for keyboard users.

Make inert elements interactive

The contenteditable and tabindex attributes, being global attributes, can be added to any element, making them focusable in the process. Focusable elements can also be focused with a mouse or pointer, by having the autofocus attribute set, or by script, such as with element.focus().

The tabindex attribute

The global tabindex attribute, introduced in attributes, enables elements that otherwise wouldn't be able to receive focus to get focus, usually with Tab, hence the name.

The tabindex attribute takes as its value an integer. A negative value makes an element focusable but not tabbable. A tabindex value of 0 makes the element focusable and tabbable, adding the element on which it's applied to the sequential focus navigation order in source code order. A value of 1 or greater makes the element focusable and tabbable, but adds it to a prioritized tabbing sequence and should be avoided.

On this page, the share button, <share-action>, is a custom element. The tabindex="0" adds this not-normally focusable element into the keyboard default tabbing order:

<share-action authors="@front-end.social/@estellevw" data-action="click" data-category="web.dev" data-icon="share" data-label="share, mastodon" role="button" tabindex="0">
  <svg aria-label="share" role="img" xmlns="http://www.w3.org/2000/svg">
    <use href="#shareIcon" />
  </svg>
  <span>Share</span>
</share-action>

There's another custom element on this page: the local navigation has a custom element with a negative tabindex value:

<web-navigation-drawer type="standard" tabindex="-1">

A tabindex attribute with a negative value makes the element focusable but not tabbable. The element is capable of receiving focus, such as using HTMLElement.focus(), but it's not part of the sequential focus navigation order. The convention for non-tabbable, focusable elements is to use tabindex="-1". If you add tabindex="-1" to an interactive element, it will no longer be tabbable.

The element.focus() method can be used to set focus to focusable elements. Browsers scroll focused elements into view. For this reason, avoid the use of element.focus({preventScroll:true}), as focusing on a non-visible element is a bad user experience.

If you want to query the document to find out which element has focus, use the read-only Document.activeElement property.

Elements with a tabindex of 1 or greater are included in a separate tab sequence. As you'll notice in the Codepen, tabbing begins in a separate sequence, in order of lowest value to highest value, before going through those in the regular sequence (no tabindex set, or tabindex="0") in source order:

tabindex with a positive value puts the element into a prioritized focus sequence, which can lead to focus order chaos. Avoid modifying the DOM order with tabindex. Not only can altered tabbing orders create bad user experiences, they are difficult for developers to manage and maintain.

The contenteditable attribute

The contenteditable attribute was discussed earlier. Setting contenteditable="true" on any element makes it editable, focusable, and part of the tab order. The focus behavior is similar to setting tabindex="0", but not the same. Nested contenteditable elements are focusable but not tabbable. To make a nested contenteditable element tabbable, add tabindex="0", which add it to the sequential focus navigation order.

Give autofocus to interactive elements

While the boolean autofocus is a global attribute that can be set on any element, it doesn't make an inert element interactive. When the page loads, the first focusable element with the autofocus attributes receives focus, as long as that element is displayed and not nested in a <dialog>.

Automatically setting focus on content can be confusing. Setting autofocus on a form control means that the form control scrolls into view on page load. All your users, including screen reader users and users with small viewports, may not "see" the instructions for the form, possibly even scrolling past the form control's normally visible label. The autofocus attribute doesn't alter the document's sequential focus navigation order. The elements in the sequence coming before the auto-focused element are skipped. For these reasons, it's not advised to include the autofocus attribute.

The exception to the "don't use autofocus" recommendation is including the autofocus attribute within <dialog> elements. When a dialog is opened, the browser automatically focuses on the first focusable interactive element within the <dialog>, which means it's unnecessary to add autofocus to an element. If you want to be sure a specific interactive element within the dialog receives focus when the dialog opens, add the autofocus attribute to that element.

<dialog open>
  <form method="dialog">
    <button type="submit" autofocus>close</button>
  </form>
</dialog>

The autofocus attribute set on the close <button> allow it to receive focus when the dialog is opened. As the first element in the dialog, it would have received focus in any case. By default, when a dialog is opened, the first focusable element within the dialog receives focus unless a different element within the dialog has the autofocus attribute set.

Make interactive elements inert

There are also HTML attributes that can remove interactive elements from the tabbing sequence. Including a negative tabindex to focusable elements, adding the disabled attribute to supporting form controls, and adding the global inert attribute to a container all make elements un-tabbable. These three attributes are NOT interchangeable.

Negative tabindex value

A tabindex attribute with a negative value makes an element focusable, but not tabbable. While adding tabindex="0" to a focusable-by-default element, including links, buttons, form controls, and elements that are contenteditable is not necessary; including a tabindex with a negative value removes normally tabbable elements from the sequential focus navigation order.

A negative tabindex value prevents keyboard users from focusing on interactive elements, but doesn't disable the element. Pointer users can still focus on the element. To disable an element, use the disabled attribute.

Disabled

The boolean disabled attribute makes the form controls on which it's applied and their descendants, if any, unfocusable. Disabled form controls can't be focused, don't get click events, and are not submitted upon form submission.

disabled is not a global attribute. It applies to <button>, <input>, <optgroup>, <option>, <select>, <textarea>, form-associated custom elements, and <fieldset>. When set on <optgroup> or <fieldset>, all the child form controls are disabled, except for the contents of the <fieldset>'s first <legend>.

The same elements that support disabled are also targetable with the :disabled and :enabled pseudo-classes. Elements that are disabled with the disabled attribute are generally styled as light gray with the user-agent stylesheet, even if an accent-color is set.

Being a boolean attribute, the presence of the attribute disables the otherwise enabled element; you can't set it to false. To re-enable a disabled element, the attribute has to be removed, generally with Element.removeAttribute('disabled').

The HTMLInputElement.disabled property lets you check if an input is disabled. As disabled is not a global attribute, it's not inherited from the HTMLElement, but every supporting element interface, like HTMLSelectElement, HTMLTextareaElement, has the same read-only property.

The disabled attribute doesn't apply to normally inert elements that are made focusable with tabindex or contenteditable, nor does it apply to the <form> element. To disable these elements, the global inert attribute can be used.

The inert attribute

When the inert global boolean attribute is added to an element, that element and all nested content become disabled, which means they cannot be clicked or tabbed to. They are also removed from the accessibility tree. While inert can be applied to any element, it's generally used for sections of content, such as offscreen or otherwise hidden content.

When applying disabled to form controls, the browser provides default styling and can be styled using the :disabled pseudo class. The inert attribute provides no visual indicators and has no matching pseudoclass (though the [inert] attribute selector matches).

Using inert on visible content without styles indicating the inertness can lead to poor user experience. As inert content is not available to screen reader users, it can lead to confusion when sighted screen reader users see content on screen that is not available to the accessibility tools. Make inertness very apparent with CSS.

Make sure that the focus never moves to non-visible content. Anything rendered off-screen that does not automatically come into view when focused should be made inert. If content is hidden, but comes into view when focused, like a skip to content link, it does not need to be made inert.

Check your understanding

Test your knowledge of focus.