Web Accessibility Testing MCP

The server tests any public URL or a raw HTML string. That covers both a live page you can't easily inspect by hand and a fragment still sitting in your editor. Each run returns a structured report. No screenshots. The assistant can summarize the violations directly.

Checks run through Deque's Axe-core engine inside a real headless browser driven by Puppeteer. These are Axe-core accessibility checks, the same kind a professional audit team runs. Because the page is fully rendered, the results reflect what users actually load, not just the source HTML. It's the same detection logic a lot of professional tooling relies on.

You choose which standards to test against with tags like wcag2aa. The server checks content against 2.0, 2.1, and 2.2 rules, so you can match the level your project actually targets instead of running everything.

Width and height are configurable, with defaults of 1280 by 800. Setting a phone-sized viewport surfaces issues that only show up on small screens. Cramped tap targets, for instance. Or content that breaks at narrow widths.

Two common failure areas get their own tools. A color contrast analyzer validates text and background pairings, while ARIA validation looks at whether attributes are used correctly and completely. Both catch problems that are tedious to verify by eye.

A rule-exploration tool explains which accessibility rules exist and what they mean. That's useful when a report flags something you don't recognize and you want context before deciding whether it's a real problem.

The server flags content that forces a specific screen orientation. That matters for users on tablets or with motor conditions, where a locked orientation can make a page unusable.