Build your 301 redirect map before you migrate, not after.

What this tool does

Provide your old site's URLs and your new site's URLs — each either a single link to a sitemap.xml (this tool fetches it, including a sitemap index's child sitemaps) or a pasted list of URLs or paths, one per line. It then builds a 301 redirect map: old URLs that are identical to a new URL once normalized are matched first, as an exact match, and everything left over is scored by how much of the wording overlaps — weighted toward the final path segment, since that's usually the strongest signal that two pages are "the same page." Matches are assigned highest-confidence first, so no URL on either side is ever used twice.

Why some URLs come back unmatched

Guessing wrong here is worse than saying nothing. A redirect map is only useful if it's trustworthy, and a plausible-looking but wrong automatic match quietly sends real visitors and search-engine crawlers to the wrong page — often unnoticed until rankings have already dropped. So any old URL that never clears a minimum confidence bar is left unmatched rather than force-matched to whatever candidate happened to score highest. As the roadmap for this tool puts it: a URL that couldn't be auto-matched is exactly the kind of judgment call worth getting right, not the kind worth guessing at.

Why a redirect map matters for a migration

Every URL that changes without a 301 redirect in place is a dead end — for a visitor who bookmarked or linked to it, and for search engines that have to rediscover and re-rank the new URL from scratch instead of carrying forward the old one's authority. Building the map before the new site goes live, rather than reactively from a spike in 404s afterward, is the difference between a migration that keeps its rankings and one that quietly loses months of them. See Redesign Without Losing Rankings for the fuller picture of what else that involves.

What to do with the result

Download the CSV for the full picture — every matched pair plus every unmatched URL, useful for reviewing or handing to a developer. Download the .htaccess snippet for the matched redirects only, ready to paste near the top of your .htaccess file, above the WordPress block. The unmatched URLs still need a person to decide where they go — that's exactly what WordPress Migration covers, planned properly rather than left half-done.