Alfa vs WAVE

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.

WAVE is a web accessibility tool that identifies many accessibility and WCAG errors and provides tools for human evaluation of web content. Its browser extensions for Chrome, Firefox, and Edge can examine password-protected, locally stored, and highly dynamic pages. The service supports page scans, scheduled site audits, intranet pages with most authentication types, and custom viewport sizes for checking responsive breakpoints. Stand-alone tools can integrate with continuous-integration systems including Selenium and Puppeteer. The API returns JSON or XML; basic analysis uses one credit, while advanced features may use two or three. New accounts receive 100 free API credits. Subscription API access has a 250-credit minimum purchase for $10 a month. Stand-alone API licenses cost $4,000 a year for Basic, $8,000 a year for Expanded, and $12,000 a year for Unlimited. The stand-alone API runs on Linux, Mac, or Windows web servers with PHP and Node installed; minimum requirements are 1 CPU, 1 GB memory, and 100 MB storage.