HTML SEO Checker
✓ Link copiedRun a quick on-page SEO audit on any page — entirely in your browser. Paste the page's HTML (View Source, then copy) and the checker parses it and grades the on-page SEO basics that search engines and social platforms rely on: the title tag and its length, the meta description and its length, how many H1 headings exist, how many images are missing alt text, and whether the page declares a canonical URL, a responsive viewport, an HTML lang attribute, and a character encoding. It also checks Open Graph and Twitter Card completeness so your links render rich previews when shared, and flags a robots meta that would keep the page out of search results. Each item is marked as looking good, worth improving, or needing a fix, with the exact value it found. Nothing is uploaded — the HTML is parsed locally — so you can audit staging pages and unpublished drafts safely. Free, fast, and private.
Paste a page's HTML above to see how it scores on the on-page SEO basics.
How to use
Open the page you want to check, view its source (right-click → View Page Source, or Ctrl/Cmd+U), and copy the HTML. Paste it into the box, or click Sample to load an example. The checker instantly tallies how many checks pass, need improvement, or need fixing, then lists each one — title, meta description, H1, image alt text, canonical, viewport, lang, charset, Open Graph, Twitter Card, and robots — with the value it found. Work down the list, fix the flagged items in your page's <head> and markup, then paste the updated HTML to confirm it now passes. Click Clear to start over.
Frequently asked questions
- What's the ideal title and meta description length?
- As a rule of thumb, a title tag reads best at roughly 30–60 characters and a meta description at roughly 70–160 characters, which is about what Google shows before truncating with an ellipsis. The checker uses these ranges: titles or descriptions outside them are flagged as worth improving, and a missing one is flagged as needing a fix. These are guidelines, not hard limits — search engines may rewrite or truncate either, so prioritise a clear, compelling summary over hitting an exact character count.
- Why does it flag images missing alt text or multiple H1s?
- Alt text describes an image for screen-reader users and gives search engines context, so every meaningful image should have an alt attribute; an explicit empty alt="" is valid for purely decorative images and is not counted as missing. For headings, a page should have exactly one H1 that states the main topic — zero H1s means the page has no clear primary heading, while several H1s can dilute that signal. These reflect common best practices rather than strict rules, so weigh them against your page's design.
- Is my HTML uploaded anywhere?
- No. The HTML you paste is parsed and analyzed entirely in your browser using JavaScript — it is never transmitted, logged, or stored on any server. That makes it safe to audit internal, staging, or unpublished pages. You can confirm this by disconnecting from the internet; the checker keeps working.