List Comparison
Compare two lists and see what is in both, only in the first, or only in the second.
About this tool
Compares two lists and reports three answers separately: shared entries, entries only in the first list, and entries only in the second.
Keeping the two "only in" answers apart is the point. Comparing a sitemap against a crawl, the URLs the sitemap lists but the crawler never reached is a completely different problem from the URLs the crawler found that the sitemap omits — the first is usually dead pages still being submitted, the second usually pages nobody meant to publish. A single "differences" list merges two findings that need different fixes.
Duplicates within a list are counted and reported, because a sitemap listing the same URL twice is worth knowing about on its own.
Common questions
Why not just show one list of differences?
Because the two directions mean different things. URLs in your sitemap that a crawler never reached are usually dead pages still being submitted; URLs a crawler found that the sitemap omits are usually pages nobody meant to publish. Merging them merges two separate jobs.
Does it ignore case and trailing slashes?
Only if you ask it to. Both are off by default, because /page and /page/ really are different URLs and treating them as the same is how a duplicate-content problem gets hidden rather than found.
What is the overlap percentage?
Shared entries as a share of all distinct entries across both lists — the Jaccard index. It is a quick sense of how far apart the two lists are, not a score.
Are duplicates within one list reported?
Yes, counted and flagged. A sitemap that lists the same URL twice, or an export with repeated rows, is worth catching even when the comparison itself comes out clean.