fast-a11y

What it does

fast-a11y checks HTML for accessibility violations without rendering it. It parses the markup directly, runs 86 of axe-core's ~95 WCAG rules, and returns violations in axe-core's format. The 9 rules it skips genuinely require a rendered DOM — things like focus management and computed styles. Everything that can be caught statically is caught.

Usage

import { check } from 'fast-a11y';

const html = '<img src="hero.jpg"><button></button>';
const result = await check(html);

for (const v of result.violations) {
  console.log(v.id, v.impact, v.nodes[0].html);
}
// 'image-alt'   'critical'  '<img src="hero.jpg">'
// 'button-name' 'critical'  '<button></button>'

from fast_a11y import check

html = '<img src="hero.jpg"><button></button>'
result = check(html)

for v in result.violations:
    print(v.id, v.impact, v.nodes[0].html)

Output format

Output matches axe-core's violation schema: id, impact (critical / serious / moderate / minor), description, nodes with html and failureSummary. Drop-in for any tooling that already consumes axe-core results.