Free Tool · Accessibility & Semantic HTML
Accessibility & Semantic HTML
for AI Agents
Enter a URL and find out whether its HTML gives AI agents the structure they need to understand and use the page — real buttons, labelled forms, logical headings and descriptive links.
8 checks, results in seconds. The page is fetched once and nothing is stored.
The tool
Check a page
What it checks
The 8 checks
Semantic elements
Looks for <main>, <nav>, <header> and <footer> (or their ARIA roles), and flags pages built almost entirely from <div>s.
Real buttons
Flags <div>s and <span>s with click handlers, role="button" stand-ins, and links like href="#" that are really actions.
Form labels
Checks that every input, select and textarea has a <label> — not just an aria-label, a title, or nothing at all.
Descriptive labels
Flags fields described only by placeholder text, and labels too vague to say what the field is for.
Autocomplete
Finds personal-data fields (name, email, phone, address, company) and checks for a valid, specific autocomplete value.
Heading hierarchy
Checks for exactly one <h1> and no skipped levels (an <h2> followed by an <h4>), and shows the full heading outline.
ARIA for custom components
Validates roles, required states (e.g. aria-checked on a custom switch), ID references, and focusable content hidden with aria-hidden.
Link text
Flags links with no text and vague anchor text such as "click here", "read more" and "learn more".
Why it matters
Why AI agents need semantic HTML
AI agents that browse and act on websites — booking, comparing, filling in forms — don't see your design. Many of them work from the page's structure, often the same accessibility tree that screen readers use, to work out what each element is and what it does.
In that tree, a <button> announces itself as something that can be pressed, a labelled field says what it expects, and headings outline the page. A <div> with a click handler is just text, and a field with only a placeholder has no name once someone starts typing.
The fixes are the same ones that make a site accessible to people using assistive technology, so the work pays off twice.
Good to know
What this tool can't see
- JavaScript-rendered content. URL checks read the HTML the server sends. If your page builds its content with JavaScript, use the Pasted HTML option with the rendered HTML copied from your browser's DevTools.
- Click handlers added by JavaScript. Frameworks like React attach handlers in code, not in the HTML, so a clickable
<div>built that way won't be detected. Check custom controls by hand. - Visual and interaction issues. This isn't a full WCAG audit — colour contrast, focus order and keyboard behaviour need a browser-based tool such as Lighthouse or axe DevTools.
This tool automates the Accessibility & Semantic HTML part of my AI Agent Website Readiness Checklist, which also covers content rendering, UI stability, LLMs.txt, WebMCP and more.