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§ · free tool
On-Page SEO checker. Score every signal you control.
Paste a page's HTML for an instant, scored on-page audit, title, meta description, headings, image alts, Open Graph, structured data and keyword density. Everything runs in your browser; nothing is uploaded.
A free online tool by Digital HeroesYour HTML is analysed in your browser, nothing is uploaded.
Can't crawl URLs across origins, so paste the page source instead.
Paste a page's HTML above (or load the sample) and run the audit to see a scored on-page SEO report.
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/ 100
Run an audit
0
Passed
0
Warnings
0
Failed
This audit covers the on-page signals you control in HTML. It can't measure off-page factors (backlinks, authority) or runtime behaviour (Core Web Vitals, JS-rendered content).
§ 02 · what you can do
Everything an on-page audit should catch.
- Score your page 0-100 with a weighted pass / warn / fail audit across every key on-page signal.
- Check your title tag for character count and pixel width against Google's ~600px display cap.
- Audit meta description length and get an instant fix tip when it's too short or too long.
- Inspect heading structure (H1, H6) and detect skipped levels or missing sub-headings.
- Find images missing alt text to fix accessibility and keyword-relevance gaps before publishing.
- Validate Open Graph, Twitter cards and JSON-LD structured data for rich social and search results.
§ 03 · how to use it
Five steps, no signup.
- Open the page you want to audit, press Ctrl+U (or right-click → View Source), select all and copy the HTML.
- Paste the HTML into the text area, or click Load sample to try a demo immediately.
- Click Audit page to run the full pass / warn / fail check set.
- Read your score out of 100 and work through each check with its fix tip.
- Scan the Top keywords list to confirm your target keyword appears at the right density.
§ 04 · faq
Frequently asked questions.
Is the On-Page SEO Checker free?
Yes, completely free for everyone. No sign-up, no account and no usage limits.
Why do I paste HTML instead of a URL?
The tool runs entirely in your browser, which can't fetch other websites' HTML across origins for security reasons. Open your page, use View Source (Ctrl+U) or Inspect, then copy the HTML and paste it here. Your HTML is analysed locally and never uploaded.
Is my HTML uploaded anywhere?
No. The audit runs entirely in your browser on your own device, so your HTML never leaves your computer and nothing is sent to a server.
Does it work offline?
Yes, once the page has loaded, the audit keeps working without a connection because all the logic runs locally in your browser.
What signals does it check?
Title tag length and pixel width, meta description, html lang, viewport, charset, favicon, a single H1, the heading outline, image alt text, visible word count, keyword density, Open Graph, Twitter cards, JSON-LD structured data, canonical, robots meta and internal vs external links.
What can't this tool measure?
It only reads the static HTML you paste, so it can't judge off-page factors like backlinks or domain authority, and it won't see text that's rendered by JavaScript after load or measure runtime signals like Core Web Vitals.
Published · Last updated .
