Lighthouse accessibility scoring

Published on Thursday, September 19, 2019 • Updated on Thursday, August 3, 2023

The Lighthouse Accessibility score is a weighted average of all accessibility audits. Weighting is based on axe user impact assessments.

Each accessibility audit is pass or fail. Unlike the Performance audits, a page doesn't get points for partially passing an accessibility audit. For example, if some buttons on a page have accessible names, but others don't, the page gets a 0 for the Buttons do not have an accessible name audit.

The following table shows the weighting for each accessibility audit. More heavily weighted audits have a bigger effect on your score. Manual audits aren't included in the table because they don't affect your score.

Audit	Weight
`[accesskey]` values are unique	7
`[aria-*]` attributes match their roles	10
Values assigned to `role=""` are valid ARIA roles	1
`button`, `link`, and `menuitem` elements have accessible names	7
Elements with `role="dialog"` or `role="alertdialog"` have accessible names	7
`[aria-hidden="true"]` is not present on the document `<body>`	10
`[aria-hidden="true"]` elements do not contain focusable descendents	7
ARIA input fields have accessible names	7
ARIA `meter` elements have accessible names	7
ARIA `progressbar` elements have accessible names	7
`[role]`s have all required `[aria-*]` attributes	10
Elements with an ARIA `[role]` that require children to contain a specific `[role]` have all required children	10
`[role]`s are contained by their required parent element	10
`[role]` values are valid	7
Elements with the `role=text` attribute do not have focusable descendents	7
ARIA toggle fields have accessible names	7
ARIA `tooltip` elements have accessible names	7
ARIA `treeitem` elements have accessible names	7
`[aria-*]` attributes have valid values	10
`[aria-*]` attributes are valid and not misspelled	10
Buttons have an accessible name	10
The page contains a heading, skip link, or landmark region	7
Background and foreground colors have a sufficient contrast ratio	7
`<dl>`'s contain only properly-ordered `<dt>` and `<dd>` groups, `<script>`, `<template>` or `<div>` elements	7
Definition list items are wrapped in `<dl>` elements	7
Document has a `<title>` element	7
`[id]` attributes on active, focusable elements are unique	7
ARIA IDs are unique	10
No form fields have multiple labels	3
`<frame>` or `<iframe>` elements have a title	7
Heading elements appear in a sequentially-descending order	3
`<html>` element has a `[lang]` attribute	7
`<html>` element has a valid value for its `[lang]` attribute	7
`<html>` element has an `[xml:lang]` attribute with the same base languge as the `[lang]` attribute	3
Image elements have `[alt]` attributes	10
Image elements do not have `[alt]` attributes that are redundant text	1
Input buttons have discernible text	10
`<input type="image">` elements have `[alt]` text	10
Elements with visible text labels have matching accessible names	7
Form elements have associated labels	7
Links are distinguishable without relying on color	7
Links have a discernible name	7
Lists contain only `<li>` elements and script supporting elements (`<script>` and `<template>`)	7
List items (`<li>`) are contained within `<ul>`, `<ol>` or `<menu>` parent elements	7
The document does not use `<meta http-equiv="refresh">`	10
`[user-scalable="no"]` is not used in the `<meta name="viewport">` element and the `[maximum-scale]` attribute is not less than 5	10
`<object>` elements have alternate text	7
Select elements have associated label elements	7
Skip links are focusable	3
No element has a `[tabindex]` value greater than 0	7
Tables have different content in the summary attribute and `<caption>`	1
Tables use `<caption>` instead of cells with the `[colspan]` attribute to indicate a caption	7
`<td>` elements in a large `<table>` have one or more table headers	10
Cells in a `<table>` element that use the `[headers]` attribute refer to table cells within the same table	7
`<th>` elements and elements with `[role="columnheader"/"rowheader"]` have data cells they describe	7
`[lang]` attributes have a valid value	7
`<video>` elements contain a `<track>` element with `[kind="captions"]`	10

Updated on Thursday, August 3, 2023 • Improve article