Alfa
Alfa · Copenhagen, Denmark · founded 2003
What it is
Alfa is a free, open accessibility conformance testing engine for websites built with HTML, CSS, and JavaScript. It checks against standards such as WCAG 2.2 using included WCAG-based rules, and developers can add pluggable rules in the ACT Rules Format. Audit results are produced in EARL Schema encoded as JSON-LD. A command-line interface can audit a single page and save results as JSON. Scraper and crawler integrations can create page snapshots and discover linked pages across a site or subdomain. Integrations are listed for frameworks and testing tools including Angular, React, Vue, Cypress, Jest, Playwright, Puppeteer, Selenium, and WebdriverIO. Developers can add custom rules and filter findings by conformance level or WCAG version. Alfa is released under the MIT license as separate npm packages. It runs in ECMAScript 2022-compatible JavaScript environments, including recent Node.js and browsers. Building it from source requires Node.js 20 or later and Yarn. The project notes that most integrations are experimental and subject to change.
For and against
For
- Free and released under the MIT license.
- Includes WCAG-based rules and supports custom rules.
- CLI can save single-page audit results as JSON.
- Scraper and crawler integrations can cover site pages.
- Supports several frameworks and testing tools.
Against
- Most integrations are experimental and may change.
- Building from source requires Node.js 20 or later and Yarn.
- Older environments are not explicitly supported.
The verdict
Alfa offers a free, extensible way to run accessibility checks in JavaScript-based website workflows. Its experimental integrations and source-build requirements are worth considering before adopting it.
Who it suits
Alfa may suit developers and teams that need to audit website accessibility and integrate checks into development or testing workflows. It is aimed at websites built with HTML, CSS, and JavaScript.
Plans and prices
Alfa
Open source · MIT license · Distributed as separate npm packages
Read 11 Oct 2026 · github.com
On the record
- Automated scans
- Yesgithub.com · read 21 Sep 2026
- Availability
- Alfa is distributed as separate packages through npm and is released under the MIT license.github.com · read 10 Oct 2026
- CI/CD integration
- Yesgithub.com · read 21 Sep 2026
- CLI
- Alfa includes a command-line interface for auditing a single page.github.com · read 11 Oct 2026
- Company
- Siteimprove says it was founded in Denmark in 2003 and lists Copenhagen among its locations.siteimprove.com · read 10 Oct 2026
- Customization
- Developers can add custom rules to the default rule set and filter results by conformance level or WCAG version.github.com · read 11 Oct 2026
- Developer integrations
- Ready-made integrations include Angular, React, Vue, Cypress, Jest, Playwright, Puppeteer, Selenium, and WebdriverIO.github.com · read 10 Oct 2026
- Development requirement
- Building Alfa from source requires Node.js version 20 or later and Yarn.github.com · read 10 Oct 2026
- Integrations
- The integrations repository lists packages for Angular, Chai, Cheerio, Cypress, Jasmine, Jest, jQuery, Playwright, Puppeteer, React, Selenium, Unexpected, Vitest, Vue, and WebdriverIO.github.com · read 11 Oct 2026
- Integration status
- Most integrations are experimental and subject to change; Cypress, Playwright, Puppeteer, and WebdriverIO integrations are actively maintained as part of the Accessibility Code Checker.github.com · read 11 Oct 2026
- License
- Alfa is released under the MIT license.github.com · read 11 Oct 2026
- Maker
- The repository identifies Siteimprove A/S as the copyright holder, and Siteimprove says it was founded in Denmark in 2003.siteimprove.com · read 11 Oct 2026
- Purpose
- Alfa is an open, standards-based accessibility conformance testing engine for websites built with HTML, CSS, and JavaScript.github.com · read 11 Oct 2026
- Remediation guidance
- Yesgithub.com · read 21 Sep 2026
- Results
- Alfa produces audit results in the Evaluation and Report Language (EARL) Schema encoded as JSON-LD.github.com · read 10 Oct 2026
- Rules
- Alfa accepts pluggable rule implementations in the ACT Rules Format and includes a set of WCAG-based rules.github.com · read 10 Oct 2026
- Rule sets
- Alfa supports pluggable rules and includes a default rule set based on WCAG.github.com · read 11 Oct 2026
- Runtime
- Alfa runs in ECMAScript 2022-compatible JavaScript environments, including recent versions of Node.js, Chrome, Firefox, Safari, and Edge.github.com · read 11 Oct 2026
