How We Built a Free WCAG 2.1 Accessibility Scanner

How We Built a Free WCAG 2.1 Accessibility Scanner Web accessibility remains one of the most overlooked aspects of web development. Most developers understand the importance—accessibility improves UX for everyone, expands market reach, and keeps you compliant with regulations like WCAG 2.1. Yet building accessible websites still feels like an afterthought for many teams. That's why we built Web Accessibility Checker —a free, open-minded scanner that instantly audits your site against WCAG 2.1 standards. In this article, I'll walk you through the architecture we chose, the challenges we faced, and how we engineered a solution that processes accessibility audits in under 20 seconds, completely free. The Problem We Solved Existing accessibility tools fall into two camps: Enterprise solutions ($5k+/month) that are overkill for indie developers and SMEs Simplistic tools that miss critical issues because they don't go deep enough We wanted something in the middle: fast, thorough, and genuine