Alfa vs veraPDF

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.

veraPDF is an open source validator for PDF/A and PDF/UA conformance. Its Implementation Checker validates all PDF/A parts and conformance levels, and performs machine checks for PDF/UA parts 1 and 2. The Policy Checker evaluates PDF Features Reports against institutional policy profiles. A Metadata Fixer makes a limited set of repairs, such as removing an incorrect PDF/A flag or repairing broken XMP when that is the only obstacle to a legitimate flag. The Reporter transforms machine-readable reports from the Implementation Checker, Policy Checker, and Metadata Fixer into other forms for downstream use. Developers can use the validation library as a Java archive through Maven, a desktop GUI, or a command-line application. Plugins can add third-party feature extraction tools to PDF Features Reports. The project describes digital preservationists and memory institutions as key users, and offers an API and test files for developers. Desktop installers are available for Windows, Mac, and Linux; these systems need Java 8 or later. veraPDF is dual licensed under GPLv3 or later and MPLv2 or later. Downloads include GPG signatures and instructions to check installer integrity. Development builds may contain bugs or missing features and come without support or guarantees. The validator costs nothing.