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Canonical URL Checker
Paste a page's HTML source to check its canonical tag, or whether it's missing or duplicated.
Open the page, right-click → View Page Source (or Ctrl/Cmd+U), select all, copy, and paste it here.
Result
Paste HTML and analyze to see results.
How to use it
- 01Open the page and view its source (Ctrl/Cmd+U).
- 02Copy the full HTML and paste it in.
- 03Optionally enter the page's own URL to check for a match.
- 04Click Check canonical tag.
Is my file uploaded?
No — this checks HTML you paste in yourself. The tool can't fetch arbitrary URLs directly because browsers block cross-site requests (CORS) for security, so it never sends your data anywhere either.
FAQ
- Why do I have to paste HTML instead of just entering a URL?
- Browsers block a webpage's JavaScript from freely reading the contents of another site (this is CORS, a core web security rule). Pasting the HTML source sidesteps that limitation without needing a server.
- Why does canonical matter?
- It tells search engines which URL is the "real" version when the same or similar content is reachable at multiple URLs, helping consolidate ranking signals to one page.
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Built by Ni Wayan Astari — Performance Marketer with a strong interest in data and technology. See more free tools or selected work.