HTML Validator
Paste your HTML and catch the common issues before you publish.
Put it online in seconds
Pagelet turns any HTML file into a live URL on your own subdomain — free, no account needed. Drag a file on the homepage or paste your code.
About the HTML Validator
A fast, practical HTML checker for the issues that actually matter: missing doctype, empty titles, images without alt text, missing viewport tags, insecure http:// references and duplicated html tags. It runs entirely in your browser with the same parser your browser uses, so nothing you paste is ever uploaded.
How to use it
- Paste your HTML into the editor.
- Press Validate — issues are listed by severity (error, warning, tip).
- Fix them, re-validate, then drag the file onto the Pagelet homepage to publish.
Frequently asked questions
Is this a full W3C validator?
No — it focuses on the common, practical issues that break pages or hurt accessibility and SEO. For exhaustive standards conformance, use the W3C validator alongside it.
Does my HTML get uploaded anywhere?
No. Validation happens locally in your browser using DOMParser.
Part of the free pagelet tool set — no account needed. Want to publish a page too? Drag a file and it's live.