On-Page SEO checker. Score every signal you control.

How to use the On-Page SEO Checker

This checker scores the on-page SEO of a single web page from its HTML. You paste the page source, your browser reads it, and the tool runs 16 checks covering the title, meta description, headings, image alt text, social tags, structured data, canonical and links, then gives a score out of 100. It is for site owners, writers and developers who want a quick pre-publish check without an account or a crawler.

Step by step

1. 1
   Copy the page's HTML

   Open the page you want to check, press Ctrl+U (View Source), select everything and copy it. The tool cannot fetch a URL for you, because a browser page is not allowed to read other sites directly.

2. 2
   Paste it into Page HTML

   Paste the source into the Page HTML box. To see a finished report first, press Load sample, which fills the box with a short example page and runs the audit straight away.

3. 3
   Run the audit

   Press Audit page. The report appears below the box in four groups: Essentials, Headings & content, Social & structured data, and Links & crawlability.

4. 4
   Work through the checks

   Each check has a green tick for a pass, an amber mark for a warning or a red cross for a fail, a short note on what was found, and a Fix line when something needs changing. Start with the red ones.

5. 5
   Review keywords and priorities

   Read Top keywords to confirm the page is about what you think it is, then use What's working and Top priorities as a short to do list. Press Clear to empty the box and reset the score.

Reading the result

• The score counts a pass as 1, a warning as half and a fail as 0, divided by the 16 checks. For example, 13 passes, 2 warnings and 1 fail give (13 + 1) ÷ 16 = 0.875, shown as 88. Scores of 80 and up read Excellent, 60 and up Good, 40 and up Needs work, and below that Poor.
• The Passed, Warnings and Failed boxes under the score count the checks in each state.
• The title passes at 40 to 60 characters and no more than about 600 pixels wide, measured in 20 pixel Arial like a desktop search result. The meta description passes at 120 to 160 characters.
• Content length passes at 300 visible words or more, warns from 30 to 299, and fails under 30. Image alt text fails when half or more of the images have no alt attribute; an empty alt counts as present, because it marks a decorative image.
• Top keywords lists up to 12 words, skipping common words and words under three letters, with how many times each appears and its share of all visible words. An in title tag means the word is also in the title or the first H1.
• Links are sorted into internal and external using the canonical URL's domain. If the page has no canonical, every full http link counts as external and only relative links count as internal.

Tips and common mistakes

• View Source shows the HTML the server sends. If the page builds its content with JavaScript, that text will be missing and the word count will look thin. In that case open Inspect, right click the html element and copy its outer HTML instead.
• A high score means the basics are in place, not that the page will rank. The tool does not see backlinks, page speed or how well the content answers the search.
• Fix the title, meta description and single H1 first. They are short edits and they shape how the page appears in results.
• Pressing Tab inside the box adds two spaces instead of moving to the next field, which helps when you edit HTML in place.

Privacy and limits

The HTML is read by your own browser and is not uploaded or saved. The page you paste is parsed as an inert document, so its scripts do not run and its images are not downloaded. Once this page has loaded, audits work without a connection.

Back to the tool

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.

Frequently asked questions.

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