4XX Pages in Sitemap
SkillWeb & browsingsitemap-4xx is an agent skill for checking whether a site's XML sitemap contains URLs that return 4XX errors. It applies to any site with a dynamically generated or manually maintained sitemap, and is useful when investigating crawl errors or after a site migration that removed pages.
Available today. Use it from your connected AI after setup.
No other account needed.
Have an agent with the sitemap-4xx skill installed.
Then ask your AI: use the 4XX Pages in Sitemap skill
What your AI can do with it
- Fetch all URLs in a sitemap and record their HTTP status codes
- Flag URLs returning 404 Not Found, 410 Gone, or 403 Forbidden
- Cross-reference flagged URLs against Google Search Console Coverage data
- Recommend 301 redirects for moved content and removal for permanently gone pages
- Explain crawl budget effects and the difference between 404 and 410 status codes
- Review metadata, rendered HTML, structured data, and response headers for violations
Getting started
- Have an agent with the sitemap-4xx skill installed.
- Provide the URL of the site's XML sitemap to check.
- Ask the agent to fetch each sitemap URL and report any that return 4XX status codes.
- For each flagged URL, decide whether to set up a 301 redirect or remove it and return 410 Gone.
- Regenerate and resubmit the sitemap, then monitor it regularly to remove deleted content promptly.
What this skill tells your AI
The instructions your AI receives, as published by thedaviddias/front-end-checklist in skills/sitemap-4xx/SKILL.md and read by ahel’s review.
Including 4XX URLs in a sitemap signals poor site maintenance to Google, wastes crawl budget on non-existent pages, and generates errors in Search Console that can mask real indexing issues.
Quick Reference
- Sitemaps should only contain URLs that return HTTP 200 and are indexable
- 4XX URLs in a sitemap waste crawl budget and cause Search Console errors
- Remove 404 pages from the sitemap or set up proper 301 redirects before adding them
- Monitor the sitemap regularly — deleted content must be removed from sitemaps promptly
Check
Fetch all URLs listed in the sitemap and record their HTTP status codes. Flag any URL returning 4XX (404 Not Found, 410 Gone, 403 Forbidden). Cross-reference against Google Search Console → Coverage for corroborating data.
Fix
For each 4XX URL: if the content moved, set up a 301 redirect to the new URL and add the new URL to the sitemap. If the content is permanently gone, return 410 Gone and remove the URL from the sitemap. Regenerate and resubmit the sitemap.
Explain
Explain why sitemaps must only contain live, indexable URLs, how 4XX URLs in sitemaps affect crawl budget allocation, and the difference between 404 and 410 status codes for deindexing.
Code Review
Review metadata generation, rendered HTML, structured data, and response headers related to 4XX Pages in Sitemap. Flag exact routes or templates where search-facing output violates the rule, and describe how to verify the final page output.
For full implementation details, code examples, and framework-specific guidance,
see references/rule.md.
Rule page: https://frontendchecklist.io/en/rules/seo/sitemap-4xx
Signals
- GitHub stars
- 74k
- Forks
- 7k
- Last commit
- Aug 2026
Questions
- When should this skill be used?
- It applies to any site with a dynamically generated or manually maintained XML sitemap. Use it when investigating crawl errors or after a site migration that removed pages.
- Why should 4XX URLs be removed from a sitemap?
- Including them signals poor site maintenance to Google, wastes crawl budget on non-existent pages, and generates Search Console errors that can mask real indexing issues.
Advanced
- Item type
- skill
- Key
sitemap-4xx- Source
- github.com/thedaviddias/front-end-checklist