methodology / Accessibility / #53

axe-core / WAVE accessibility scan

#53 · Recommended · Web Quality · weighted · Accessibility · weight 2.7% · impl implemented · method v1.2.0

Web Quality factor

This factor is part of Web Quality — the weighted 0..100 score that sits above Web Standards. Its weight depends on what kind of site is being measured. Web Standards items take priority; this factor only enters the score once Web Standards passes.

Base weight: 0.8 applied to every site type unless overridden below
Why this weight: axe-core full audit — beyond the bar. The bar catches the show-stoppers; this catches the long tail.

Per-site-type overrides

Site type	Weight	Δ vs base
E-commerce	0.9	+0.1
Personal site	0.4	-0.4
Education	1.0	+0.2
Government	1.2	+0.4

Site types not listed inherit the base weight.

Same factor, two depths.

What we measure

Accessibility scanners flag concrete WCAG violations: missing labels, low contrast, broken keyboard navigation. Each issue is a real exclusion of disabled users — not a theoretical compliance question.

How to improve your score

Run axe-core (or Lighthouse) against your site and fix the reported issues. Most are 5-minute fixes — adding labels, adjusting colors, fixing tab order.

Facts

Ticket

WEBQ-53

Implementation notes

Already in PSI accessibility audits — just expose the issue list with severity and node selector.

Scoring

Scoring formulas are versioned with the methodology. The current method (v1.2.0) maps raw measurements to pass, warn, fail. Factor weights determine how much each contributes to the composite — see the methodology index for the full table.

Cited by these standards

Standards in the Standards Library whose satisfiedBy requirement tree references this factor. Each link goes to the standard's full entry — methodology, scope, and the other factors it relies on.

Public Sector Bodies Accessibility Regulations 2018 Accessibility UK UK public-sector websites and mobile apps must meet WCAG 2.1 AA and publish an accessibility statement. GDS audits a sample every year.
WCAG 2.1 Level AA Accessibility global The version of WCAG most regulators actually wrote into law. EAA, UK PSBAR, and France's RGAA all cite 2.1 AA — even after 2.2 shipped.
WCAG 2.2 Level AA Accessibility global The web's de-facto baseline for accessibility. If a courtroom or compliance auditor asks whether your site is accessible, this is what they'll measure against.

Version history

Version	Change	Date
v1.2.0	Factor introduced. Status: live. Scoring impl: implemented.	2026-04-25

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