404 Pattern Analyser
Paste a 404 URL list (from GSC coverage report, server logs, or a crawler). The analyser clusters URLs by shared patterns, common prefixes, suspicious parameters, and suggests mass-redirect rules that collapse hundreds of 404s to a handful of regexes.
Technical SEO Intelligence
Most 404 lists are not random: they follow 5 to 10 patterns that collapse to a handful of redirect rules.
Dev teams see 10,000 404s and freeze. Pattern analysis almost always shows the same picture: a deprecated path prefix, a parameter format that no longer works, a trailing-slash inconsistency, a migration from .html to clean URLs. One regex rule in Cloudflare or .htaccess kills thousands of 404s.
Paste 404 URLs
One URL per line
Paste from GSC Coverage, server logs, or any 404 export
Frequently asked questions
Where do I get a 404 URL list?
Google Search Console (Pages and Not found 404), server logs filtered to 404 status, or a desktop crawler export.
What does "pattern analysis" mean?
Clustering 404 URLs by shared path prefixes, parameter patterns, and templates. Collapses hundreds of individual 404s to a handful of redirect rules.
Why not redirect every 404 individually?
For 10 URLs it is fine. For 10,000 URLs individual redirects are unmaintainable. Pattern rules in Cloudflare or .htaccess cover thousands with one rule.
What URL patterns typically show up?
Legacy .html URLs after a clean-URL migration, old /blog/post/N numeric IDs, retired product paths, bot-probe attempts (wp-admin, .env), framework artefacts (_next, chunks).
Should I redirect bot-probe URLs?
No. Return 410 or block at the edge. Redirecting /wp-login.php to your homepage is cosmetic.
What is a 410 vs 404?
410 Gone means permanently removed, deliberately. Google de-indexes 410s faster than 404s. Use 410 when the URL is truly gone and you want it out of the index.
Can one regex rule cover 10,000 URLs?
Yes. One well-written pattern often collapses an entire class of 404s. The tool suggests patterns.
What is the output format?
Grouped list of templates with counts. Translate the top templates into Cloudflare Bulk Redirects CSV or .htaccess/Nginx rules using the generators on this site.
How many URLs can the tool handle?
In-browser up to about 50,000 URLs. Larger: split into batches.
What is a crawl trap?
A pattern where the URL generator produces infinite variants (
?page=99999 keeps rendering content). Shows up as repeated template matches with high counts.Should I act on single-URL patterns?
Lower priority. The ROI is on patterns with 10+ URLs matching.
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