HeroTools / SEO & Marketing
Local · Private · Free

On-Page SEO Checker

Paste a page's HTML for an instant, scored on-page audit — title, meta, headings, image alts, Open Graph, structured data and more. All on your device.

🔒 Your HTML is analysed in your browser — nothing is uploaded.
Can't crawl URLs across origins — 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.

Essentials

Headings & content

Social & structured data

Links & crawlability

Top keywords

    No visible body text detected.
    What's working
      Top priorities
        —/ 100
        Run an audit
        0Passed
        0Warnings
        0Failed

        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).

        About On-Page SEO Checker

        On-Page SEO Checker is a free, private seo & marketing tool that runs entirely in your web browser. Paste a page's HTML for a scored on-page SEO audit covering the title tag, meta description, heading structure, image alt text, canonical, robots, Open Graph, Twitter cards, structured data and keyword density. Because everything happens locally on your device, your HTML is never uploaded to a server, there is no sign-up or installation required, and it keeps working offline. It is handy for marketers, editors and developers checking a page before publishing. Like every HeroTool by Digital Heroes, On-Page SEO Checker is 100% free with no limits.

        How to use On-Page SEO Checker

        1. Open On-Page SEO Checker — it runs entirely in your browser, with no signup.
        2. Fill in the fields or choose the options you want.
        3. Adjust the options to match exactly what you need.
        4. Copy or download your result — it is free, and your data stays on your device.

        Frequently asked questions

        Is On-Page SEO Checker free?

        Yes — On-Page SEO Checker is 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 cannot fetch other websites' HTML across origins for security reasons. Open your page, use View Source (Ctrl+U) or right-click and 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 uploaded to a server.

        Does it work offline?

        Yes. HeroTools is a Progressive Web App — once the page has loaded it keeps working offline, and you can install it as an app from your browser.

        What does On-Page SEO Checker do?

        Paste a page's HTML for a scored on-page SEO audit covering titles, meta tags, headings, image alts, Open Graph, structured data and keyword density.

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