Alfa vs Horn
Alfa
github.com
Horn
github.comSide by side
| Figure | Alfa | Horn |
|---|---|---|
| Price from | Free | — |
| Free plan | Yes | — |
| Free trial | — | — |
| Open source | — | — |
| Web | Yes | Yes |
| Windows | Yes | Yes |
| macOS | Yes | Yes |
| Linux | Yes | Yes |
| API | Yes | Yes |
| Self-hosted | Yes | Yes |
| Plans published | 1 | 0 |
| Spec score · Accessibility Testing Software | 9.0 (#8) | 7.7 (#103) |
| Automated scans | Yes | Yes |
| CI/CD integration | Yes | Yes |
| Customization | Developers can add custom rules to the default rule set and filter results by conformance level or WCAG version. | The site says developers can add custom checks with the Check trait. |
| Free plan | Yes | Yes |
| License | Alfa is released under the MIT license. | The project site says Horn is released under the MIT and Apache 2.0 licenses. |
| 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 accessibility checker based on the Matterhorn Protocol. |
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.