Overview Open Chrome DevTools Simulate mobile devices with Device Mode Performance insights: Get actionable insights on your website's performance Lighthouse: Optimize website speed Animations: Inspect and modify CSS animation effects Changes: Track your HTML, CSS, and JavaScript changes Coverage: Find unused JavaScript and CSS CSS Overview: Identify potential CSS improvements Issues: Find and fix problems Media: View and debug media players information Memory Inspector: Inspect JavaScript ArrayBuffer Network conditions: Override the user agent string Security: Understand security issues Search: Find text across all loaded resources WebAuthn: Emulate authenticators
Overview Open Chrome DevTools Simulate mobile devices with Device Mode Performance insights: Get actionable insights on your website's performance Lighthouse: Optimize website speed Animations: Inspect and modify CSS animation effects Changes: Track your HTML, CSS, and JavaScript changes Coverage: Find unused JavaScript and CSS CSS Overview: Identify potential CSS improvements Issues: Find and fix problems Media: View and debug media players information Memory Inspector: Inspect JavaScript ArrayBuffer Network conditions: Override the user agent string Security: Understand security issues Search: Find text across all loaded resources WebAuthn: Emulate authenticators

Accessibility features reference

Published on

This page is a comprehensive reference of accessibility features in Chrome DevTools. It is intended for web developers who:

The purpose of this reference is to help you discover all of the tools available in DevTools that can help you examine a page's accessibility.

See Navigating Chrome DevTools With Assistive Technology if you're looking for help on navigating DevTools with an assistive technology like a screen reader.

Overview of accessibility features in Chrome DevTools

This section explains how DevTools fits into your overall accessibility toolkit.

When determining whether a page is accessible, you need to have 2 general questions in mind:

  1. Can I navigate the page with a keyboard or screen reader?
  2. Are the page's elements properly marked up for screen readers?

In general, DevTools can help you fix errors related to question #2, because these errors are easy to detect in an automated fashion. Question #1 is just as important, but unfortunately DevTools can't help you there. The only way to find errors related to question #1 is to try using a page with a keyboard or screen reader yourself. See How To Do An Accessibility Review to learn more.

Audit a page's accessibility

In general, use the accessibility checks under the Lighthouse panel to determine if:

To audit a page:

  1. Go to the URL that you want to audit.

  2. In DevTools, click the Lighthouse tab. DevTools shows you various configuration options.

    Configuring an accessabillity scan in Lighthouse panel.

    Figure 1. Configuring audits

    Note: The screenshots in this section were taken with Chrome 69. In the screenshots, the tab is still named Audits but it was renamed into Lighthouse in Chrome 83 You can check what version you're running at chrome://version. The Audits panel UI will look different in some earlier or later versions of Chrome, but the general workflow is the same.

  3. For Device, select Mobile if you want to simulate a mobile device. This option changes differently your user agent string and resizes the viewport. If the mobile version of the page displays differently than the desktop version, this option could have a significant effect on the results of your audit.

  4. In the Lighthouse section, make sure that Accessibility is enabled. Disable the other categories if you want to exclude them from your report. Leave them enabled if you want to discover other ways to improve the quality of your page.

  5. The Throttling section lets you throttle the network and CPU, which is useful when analyzing load performance. This option should be irrelevant to your accessibility score, so you can use whatever you prefer.

  6. The Clear Storage checkbox lets you clear all storage before loading the page, or preserve storage between page loads. This option is also probably irrelevant to your accessibility score, so you can use whatever you prefer.

  7. Click Generate Report. After 10 to 30 seconds, DevTools provides a report. Your report gives you various tips on how to improve the page's accessibility.

    A report.

    Figure 2. A report

  8. Click an audit to learn more about it.

    More information about an audit.

    Figure 3. More information about an audit

  9. Click Learn More to view that audit's documentation.

    Viewing an audit's documentation.

    Figure 4. Viewing an audit's documentation

See also: aXe extension

You may prefer to use the aXe extension or Lighthouse extension rather than the Lighthouse panel that is available by default in Chrome. They generally provide the same information, since aXe is the underlying engine that powers the Lighthouse panel. The aXe extension has a different UI and describes audits slightly differently. One advantage that the aXe extension has over the Audits panel is that it lets you inspect and highlight failing nodes.

The aXe extension.

Figure 5. The aXe extension

The Accessibility pane

The Accessibility pane is where you can view the accessibility tree, ARIA attributes, and computed accessibility properties of DOM nodes.

To open the Accessibility pane:

  1. Click the Elements tab.
  2. In the DOM Tree, select the element which you want to inspect.
  3. Click the Accessibility tab. This tab may be hidden behind the More Tabs More Tabs button.
Inspecting an h1 element of the DevTools homepage in the Accessibility pane.

Figure 6. Inspecting the h1 element of the DevTools homepage in the Accessibility pane

View an element's position in the accessibility tree

The accessibility tree is a subset of the DOM tree. It only contains elements from the DOM tree that are relevant and useful for displaying the page's contents in a screen reader.

Inspect an element's position in the accessibility tree from the Accessibility pane.

The Accessibility Tree section

Figure 7. The Accessibility Tree section

This view allows you to explore only a single node and its ancestors. To explore the whole accessibility tree, follow the steps below.

(Preview) Explore the full-page accessibility tree

The full-page view of the accessibility tree allows you to explore the whole tree and helps you better understand how your web content is exposed to assistive technology.

To explore the accessibility tree:

  1. Check Science Enable full-page accessibility tree.

  2. On the action bar at the top, click Reload DevTools.

    Enable full-page accessibility tree
  3. In the upper right corner of the Elements panel, toggle the Accessibility Switch to Accessibility Tree view button.

    Full-page view of the accessibility tree
  4. Browse the accessibility tree. You can expand nodes or click to see details under Computed properties.

  5. Select a node and click the Accessibility Switch to DOM tree view button to toggle back to DOM tree.

    The corresponding DOM node is selected now. This is a great way to understand the mapping between the DOM node and its accessibility tree node.

Note: Our team is still actively working on this preview feature. We are looking for your feedback to further improve it!

View an element's ARIA attributes

ARIA attributes ensure that screen readers have all of the information that they need in order to properly represent a page's contents.

View an element's ARIA attributes in the Accessibility pane.

The ARIA Attributes section

Figure 8. The ARIA Attributes section

View an element's computed accessibility properties

Note: If you're looking for computed CSS properties, see the Computed tab.

Some accessibility properties are dynamically calculated by the browser. These properties can be viewed in the Computed Properties section of the Accessibility pane.

View an element's computed accessibility properties in the Accessibility pane.

The Computed (Accessibility) Properties section.

Figure 9. The Computed (Accessibility) Properties section

View the contrast ratio of a text element in the Color Picker

Some people with low vision don't see areas as very bright or very dark. Everything tends to appear at about the same brightness, which makes it hard to distinguish outlines and edges. Contrast ratio measures the difference in brightness between the foreground and background of text. If your text has a low contrast ratio, then these low vision users may literally experience your site as a blank screen.

The Color Picker can help you make sure that your text meets recommended contrast ratio levels:

  1. Click the Elements tab.

  2. In the DOM Tree, select the text element that you want to inspect.

    Inspecting a paragraph in the DOM Tree.

    Figure 10. Inspecting a paragraph in the DOM Tree

  3. In the Styles pane, click the color square next to the element's color value.

    The color property of the element.

    Figure 11. The color property of the element

  4. Check the Contrast Ratio section of the Color Picker. One checkmark means that the element meets the minimum recommendation. Two checkmarks means that it meets the enhanced recommendation.

    The Contrast Ratio section of the Color Picker shows 2 checkmarks and a value of 16.10.

    Figure 12. The Contrast Ratio section of the Color Picker shows 2 checkmarks and a value of 16.10

  5. Click the Contrast Ratio section to see more information. A line appears in the visual picker at the top of the Color Picker. If the current color meets recommendations, then anything on the same side of the line also meets recommendations. If the current color does not meet recommendations, then anything on the same side also does not meet recommendations.

    The Contrast Ratio Line in the visual picker.

    Figure 13. The Contrast Ratio Line in the visual picker

Last updated: Improve article

We serve cookies on this site to analyze traffic, remember your preferences, and optimize your experience.