Check redirect-map coverage against an old-URL inventory

Compare a pasted old-URL inventory with the source URLs in your redirect map. The checker runs in this browser and reports list coverage only: it does not fetch destinations or confirm that a redirect works.

Paste the same scope of old URLs that you intend to migrate. Absolute URLs and paths are accepted. Blank lines and lines beginning with `#` are ignored. For comparison, the host and fragment are omitted; path and query remain significant.

Each non-empty map row needs exactly two tab-separated values. The source is compared to the inventory using the same host- and fragment-free path-and-query key. Destinations must be absolute HTTP or HTTPS URLs. Blank lines and lines beginning with `#` are ignored.

Compare lists Copy report

Paste both lists, then compare them.

How to read the report

• Missing source: an inventory key has no matching map row. It may need a redirect, or the URL may have a documented no-redirect outcome.
• Duplicate source: the same normalized source appears more than once in the inventory or map. Review it before relying on coverage totals.
• Unused map source: a map source is absent from the inventory supplied. Check whether the inventory is incomplete or the extra row is intentional.
• Duplicate destination: multiple distinct sources point to the same normalized destination. This is a review flag, not a verdict that the mapping is wrong.

Comparison ignores host names and fragments but keeps query strings, so old URLs on different hostnames with the same path and query compare as the same key. It does not infer URL equivalence, decide whether content is relevant, or inspect the new site. Review exceptions and test redirects separately.

Migration review context

Google's site-move guidance recommends mapping old URLs to corresponding new URLs and testing redirects. This local comparison can help find inventory rows without map entries, but it does not perform Google's recommended redirect tests. HTTP redirect behavior is defined by the response a server actually returns; pasted lists alone cannot establish that behavior.

• Google Search Central: site moves with URL changes — URL mapping, redirects, sitemap updates, and monitoring.
• RFC 9110: HTTP Semantics — HTTP response and redirection semantics.
• 301 redirect rule generator — format reviewed mappings as Apache or Nginx rule text.
• Website migration checklist — record per-URL status, redirect destination, and other observed checks.

This browser-local checker does not save or upload your lists. Its results describe only the text you paste and cannot confirm server configuration, response status, redirect chains, loops, or destination quality.