XML Sitemap Best Practices: Format, Limits, lastmod and Audits
The rules that make an XML sitemap useful: format and limits, sitemap index files, which URLs to list, accurate lastmod, submission, extensions and auditing.
Sitemap Hygiene Auditor
Check sitemap syntax, limits, duplicates and lastmod patterns — and verify a sample of destinations.
What this tool does
Reads XML sitemaps and sitemap indexes (including gzip) with safe, bounded parsing, then checks protocol validity, duplicates, scope and date patterns, and verifies a deterministic sample of destination pages.
What you get
- Per-file validity and protocol limits
- lastmod distribution and identical-date review
- Sampled destinations: status, redirects, canonical, noindex
- CSV export
Scope
Up to 20 sitemap files and 50,000 URLs; up to 40 destinations sampled.
Pages are fetched politely by BacklnkBot, robots.txt is respected, and only public websites can be audited. Every finding shows the evidence it is based on and when it was measured.
Limitations
- • Identical lastmod values are flagged for review — they do not prove fabricated dates.
- • Google documents that it ignores priority and changefreq; that is vendor behaviour, separate from protocol validity.
- • Actual indexing and Search Console data are not inferred.
Frequently asked questions
- Why only a sample of destinations?
- Checking every URL of a large site would be slow and impolite. The sample is spread across the sitemap and the coverage numbers show exactly what was checked.
Guides
Learn the topic behind the sitemap audit check
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