How do Lighthouse scores relate to WCAG 2.1

[Aprahanti1969]

Hi,

I'm running an accessibility audit of our intranet using the Lighthouse tool in order to comply with legislation which comes into force in the UK in September. This states that all public sector websites (internal and external) must comply with WCAG 2.1 Level AA accessibility guidelines.

The Lighthouse tool is great and we're getting good scores, but I am not clear on how the scores relate to WCAG 2.1 Level AA.

Your advice would be much appreciated.

Thanks,

Nordin Zaoui

[patrickhulce]

Thanks for filing @Aprahanti1969!

tl;dr - Lighthouse covers much, but not all of WCAG 2.1 Level AA requirements and there are things you'll need to check manually.

Lighthouse runs all the wcag2a and wcag2aa tagged rules in axe-core with a few exceptions.

lighthouse/lighthouse-core/gather/gatherers/accessibility.js

Lines 24 to 51 in 252232d

	return window.axe.run(document, {
	elementRef: true,
	runOnly: {
	type: 'tag',
	values: [
	'wcag2a',
	'wcag2aa',
	],
	},
	resultTypes: ['violations', 'inapplicable'],
	rules: {
	'tabindex': {enabled: true},
	'accesskeys': {enabled: true},
	'table-fake-caption': {enabled: false},
	'td-has-header': {enabled: false},
	'marquee': {enabled: false},
	'area-alt': {enabled: false},
	'aria-dpub-role-fallback': {enabled: false},
	'aria-hidden-body': {enabled: false},
	'duplicate-id-active': {enabled: false},
	'duplicate-id-aria': {enabled: false},
	'html-xml-lang-mismatch': {enabled: false},
	'blink': {enabled: false},
	'server-side-image-map': {enabled: false},
	'aria-hidden-focus': {enabled: false},
	'form-field-multiple-labels': {enabled: false},
	'aria-input-field-name': {enabled: false},
	'aria-toggle-field-name': {enabled: false},

axe-core can't fully automate WCAG 2.1 checks though, so there are still going to be some things you need to check. I'd still refer to the w3 checklists for final compliance.

[Aprahanti1969]

Thanks Patrick, Regards, Nordin. From: Patrick Hulce [mailto:notifications@github.com] Sent: 05 August 2019 17:17 To: GoogleChrome/lighthouse <lighthouse@noreply.github.com> Cc: Nordin Zaoui <Nordin.Zaoui@ofgem.gov.uk>; Mention <mention@noreply.github.com> Subject: Re: [GoogleChrome/lighthouse] How do Lighthouse scores relate to WCAG 2.1 (#9507) Thanks for filing @Aprahanti1969<https://github.com/Aprahanti1969>! tl;dr - Lighthouse covers much, but not all of WCAG 2.1 Level AA requirements and there are things you'll need to check manually. Lighthouse runs all the wcag2a and wcag2aa tagged rules in axe-core with a few exceptions. https://github.com/GoogleChrome/lighthouse/blob/252232db9263750435e471da7ea2da1f97ef0d61/lighthouse-core/gather/gatherers/accessibility.js#L24-L51 axe-core can't fully automate WCAG 2.1 checks though<https://www.deque.com/blog/support-for-wcag-2-1-in-axe-core/>, so there are still going to be some things you need to check. I'd still refer to the w3 checklists<https://www.w3.org/WAI/WCAG21/quickref/?currentsidebar=%23col_customize&levels=aaa> for final compliance. — You are receiving this because you were mentioned. Reply to this email directly, view it on GitHub<#9507?email_source=notifications&email_token=AMY7J7D6OJ7EKIJ3V7QXLHTQDBG6BA5CNFSM4IJIE56KYY3PNVWWK3TUL52HS4DFVREXG43VMVBW63LNMVXHJKTDN5WW2ZLOORPWSZGOD3SKEFQ#issuecomment-518300182>, or mute the thread<https://github.com/notifications/unsubscribe-auth/AMY7J7HAQ3ERVE2ISC4HAKLQDBG6BANCNFSM4IJIE56A>. [] This message may be confidential, privileged or otherwise protected from disclosure. It does not represent the views or opinions of Ofgem unless expressly stated otherwise. If you have received this message by mistake, please contact the sender and immediately delete the message from your system; you should not copy the message or disclose its contents to any other person or organisation.