Inspiration
Web accessibility is often treated as an afterthought, even though millions of users rely on accessible websites every day. While building and testing modern web applications, we realized that many existing tools either oversimplify accessibility checks or give misleading results due to client-side limitations. This motivated us to build AllyCheck, a tool that performs real, standards-based accessibility audits instead of surface-level checks, helping developers confidently evaluate accessibility compliance early in development.
What it does
AllyCheck – Web Accessibility Scanner is a professional web accessibility auditing tool that scans any public website and detects violations based on WCAG 2.1 / 2.2 guidelines. It renders pages in a real browser environment, executes JavaScript, and analyzes the fully hydrated DOM to identify accessibility issues across structure, forms, keyboard navigation, ARIA usage, color contrast, and more. The tool generates a clear, severity-based audit report with actionable remediation guidance.
How we built it
We built AllyCheck using a server-side architecture to avoid browser security and CORS limitations. A headless browser (Playwright/Puppeteer) is used to load and render web pages exactly as users experience them. We integrated axe-core as the primary accessibility rules engine to ensure industry-standard accuracy. The backend performs the audit and returns structured results, while the frontend presents findings in a clean, developer-friendly report with severity levels and WCAG references.
Challenges we ran into
One major challenge was avoiding false “100% accessible” results caused by client-side DOM restrictions when scanning external URLs. Another challenge was ensuring JavaScript-heavy and dynamically rendered content was fully analyzed instead of scanning raw HTML. Balancing performance with audit depth and clearly communicating scan limitations (such as authentication-protected content) also required careful design decisions.
Accomplishments that we're proud of
Built a realistic accessibility scanner that avoids common false positives and false negatives
Successfully detected known accessibility violations on intentionally broken WCAG test pages
Implemented a server-side scanning model aligned with professional auditing tools
Generated clear, structured reports mapped directly to WCAG criteria
Created a solution suitable for academic, enterprise, and developer use
What we learned
We learned that accurate accessibility testing goes far beyond static HTML analysis. Many accessibility issues are behavioral and only appear after JavaScript execution and user interaction. We also gained a deeper understanding of WCAG standards, ARIA best practices, and the limitations of automated testing—reinforcing the importance of transparency and proper tooling in accessibility workflows.
What's next for AllyCheck – Web Accessibility Scanner
Next, we plan to add authenticated page scanning, improved reporting with accessibility scores and trends, CI/CD integration for automated checks, and exportable reports for compliance documentation. We also aim to support partial manual review workflows and browser extension support to further bridge the gap between automated and real-world accessibility testing.
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