F Kitchen Sink

Accessibility audit rules

Image alt text

Accessibility rule handbook metadata

Rule
DET.A11Y.GENERIC.IMAGES_ALT · lane deterministic · scope generic
Page status
current
page_version
2c42060327707ca69218f5a99ced113441643783e2092a0680408e23fd17c3ec
generated_at
2026-05-26T08:51:23.000Z
registry_fingerprint
e11a2939d018a45bae7d6e23364aba2ae4e13f190d942f49891c89ea84c44c46

How this rule is checked

Deterministic lane — scope generic. Detected by det-a11y-generic-*.check.js or the axe lane for WCAG-tagged violations.

  • Harness: auditor-tests/invoke-a11y-ruleset-harness.sh on the Before fixture.
  • Audit: analyze-website-a11y.mjs --only-deterministic-rule-ids DET.A11Y.GENERIC.IMAGES_ALT

Module: docs/design/a11y-audit/deterministic-a11y-rules.md#det-a11y-generic-images-alt. See Before / After below.

Purpose

Informative images need meaningful alt.

Passing signals

  • DOM and/or repo signals satisfy the rule implementation in tools/website-a11y-auditor.
  • For axe-backed WCAG criteria, use --lanes axe,det with an appropriate --standard preset.

Failing signals

  • Auditor emits a finding with ruleId DET.A11Y.GENERIC.IMAGES_ALT on the crawled URL.
  • Harness: auditor-tests/invoke-a11y-ruleset-harness.sh DET.A11Y.GENERIC.IMAGES_ALT expects ≥1 finding on the Before fixture.

Before example

Before (failing example)

Decorative-only alt missing on informative graphic.

After example

After (passing example)

Architecture diagram: three-tier flow

Alt describes the diagram purpose.

Evidence and remediation

  1. Reproduce with analyze-website-a11y.mjs --only-deterministic-rule-ids DET.A11Y.GENERIC.IMAGES_ALT when lane is deterministic.
  2. Apply the After markup pattern (or fix generator source for KS rules).
  3. Re-run harness or audit until the rule is clean on the target URL.