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Compare HTML and HTTP Link canonicals safely
Canonical conflicts — multiple tags, header vs HTML mismatch, relative paths, http on an https site, or cross-domain surprises — create indexing ambiguity. Inspection must use the same SSRF-safe fetch path as other DevNestro URL tools.
Why this is worth doing in the browser
DevNestro’s Canonical URL Checker fetches with the safe public fetcher, extracts rel=canonical from HTML and Link headers, and reports Present / Missing / Needs Review findings for multiples, self-reference, cross-domain, relative vs absolute, and scheme. Rate limited.
How to use the tool
Enter the public page URL, review extracted values and findings, fix template or CDN header conflicts, then re-check. SEO Preview and Redirect Checker complement the workflow.
- Prefer a single absolute https canonical.
- Align HTML and Link header when both exist.
- Cross-domain canonicals need an intentional reason.
- Private URLs cannot be fetched.
Privacy
DevNestro fetches the public URL you enter; content is used only for the on-page report.
Canonical unsure? Run Canonical URL Checker on the live public URL and clear Needs Review items.