HTML Heading Validator
NewCheck h1–h6 structure for SEO — skips, multiple h1s, empty headings.
See how it works
Watch a quick simulation of this tool in action — no file needed.
How to use HTML Heading Validator
Follow these steps — everything happens instantly in your browser.
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Step 1. Paste an HTML fragment with heading tags.
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Step 2. Click Validate headings.
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Step 3. Review the issues and the indented outline.
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Step 4. Fix the structure and re-validate.
Why use this tool
Private by design
All processing happens locally in your browser. Open DevTools → Network and you'll see zero file uploads. Ever.
Instant
No upload wait, no queue, no server round-trip. Results appear the moment you drop a file.
Free & unlimited
No accounts, no watermarks, no daily caps. Use it as many times as you like, forever.
Works everywhere
Desktop, tablet or phone — every tool is responsive and installable as a PWA for offline use.
Frequently asked questions
Everything you might want to know about html heading validator.
HTML Entities Encode / Decode
Escape & unescape HTML entities — live, no uploads.
HTML to Markdown Converter
Convert HTML to clean Markdown via DOMParser — no regex hacks.
XML Formatter & Minifier
Beautify or minify XML — handles attributes, CDATA, comments.
Markdown Preview
Write Markdown and see the rendered HTML live — side by side.