Alfa vs Horn
Alfa
github.comHorn
horn.reportSide by side
| Figure | Alfa | Horn |
|---|---|---|
| Price from | Free | Free |
| Free plan | Yes | Yes |
| Free trial | — | — |
| Open source | — | — |
| Web | Yes | Yes |
| Windows | Yes | Yes |
| macOS | Yes | Yes |
| Linux | Yes | Yes |
| API | Yes | — |
| Self-hosted | Yes | Yes |
| Plans published | 1 | 1 |
| Spec score · Accessibility Testing Software | 9.0 (#8) | 8.3 (#53) |
| Integrations | The integrations repository lists packages for Angular, Chai, Cheerio, Cypress, Jasmine, Jest, jQuery, Playwright, Puppeteer, React, Selenium, Unexpected, Vitest, Vue, and WebdriverIO. | The repository documents GitHub Actions and GitLab CI examples, as well as SARIF output for GitHub Code Scanning. |
| License | Alfa is released under the MIT license. | The homepage states that Horn is released under the MIT / Apache 2.0 License. |
| Purpose | Alfa is an open, standards-based accessibility conformance testing engine for websites built with HTML, CSS, and JavaScript. | Horn is an open-source PDF/UA checker based on the Matterhorn Protocol. |
| Standards | It tests against accessibility standards such as the Web Content Accessibility Guidelines (WCAG). | It automates 87 machine-checkable Matterhorn Protocol 1.1 conditions, surfaces 48 human-judgment conditions for manual review, and identifies 2 conditions without a defined test. |
Plans
In their own words
Alfa
Alfa is a free, open accessibility testing engine for websites built with HTML, CSS, and JavaScript. It checks pages against accessibility standards such as WCAG, using included rules or pluggable rules in the ACT Rules Format. Developers can add custom rules and filter results by conformance level or WCAG version. Audit output follows the Evaluation and Report Language schema as JSON-LD, and the command-line interface can audit a single page and save results as JSON. Scraper and crawler tools create page representations and discover pages across a site or subdomain. Ready-made integrations cover frameworks and test tools including Angular, React, Vue, Cypress, Jest, Playwright, Puppeteer, Selenium, and WebdriverIO. Alfa is distributed as separate npm packages under the MIT license. It runs in ECMAScript 2022-compatible JavaScript environments, including recent Node.js and browser versions. Building from source requires Node.js 20 or later and Yarn. The project says most integrations are experimental and may change; older environments may be targetable from source but are not explicitly supported.