How to use
In “Validate a sitemap”, paste the contents of sitemap.xml or open a .xml / .xml.gz file.
Review errors and warnings and the URL list (count, lastmod, hreflang). Save the URL list as CSV.
To create one, enter one URL or path per line in “Create a sitemap”. Add a date after a tab or comma to set lastmod.
Above 50,000 URLs the output is split automatically with a sitemap index. Download as ZIP or gzip.
Use “Compare two” to see which URLs were added or removed between versions of a site.
What it does
Strict checks with line numbers
XML syntax errors are pinpointed, and namespace, relative URLs, # fragments, unencoded characters, duplicates, mixed hosts or http/https, lastmod format and future dates, priority and changefreq values are checked. Repeated problems are grouped with counts.
hreflang reciprocity
Checks that each xhtml:link alternate set includes the page itself, that linked pages link back, and that language codes are valid.
Create correct sitemaps
URLs are escaped and percent-encoded, duplicates merged (keeping the newest date), output split per 50,000 URLs with a sitemap index, and gzip supported. changefreq/priority, which Google ignores, are off by default.
Compare two sitemaps
XML or plain URL lists: see added and removed URLs and those whose lastmod changed.
Use cases
- Quickly create a sitemap.xml for a site without a CMS
- Find out why Search Console says “Couldn’t read sitemap”
- Check that no URLs disappeared after a site redesign
- Verify hreflang links are reciprocal on a multilingual site
- Split more than 50,000 product URLs into files with a sitemap index
Supported formats
Input
Output
Capability matrix
| Feature | Support | Notes |
|---|---|---|
| Validate sitemaps and sitemap indexes (with line numbers) | Supported | — |
| Create from a URL list, split per 50,000, build an index | Supported | — |
| hreflang (xhtml:link) reciprocity check | Supported | — |
| Image, video and news extensions | Partial | Counted only; their contents are not validated |
| Crawl a site to collect URLs | Not supported | — |
| Fetch a sitemap by URL / check HTTP status of each URL | Not supported | Paste the contents instead |
Limits & notes
- Nothing is fetched. Open sitemap.xml in your browser and paste it, or open the file.
- Files up to 60 MB; the URL table shows 500 rows (checks and CSV cover everything).
- Per-file limits (50,000 URLs, 50 MB uncompressed) follow the sitemap protocol.
- Entities declared in a DOCTYPE are never expanded, for safety.
Privacy & safety
Sitemaps and URL lists are processed in your browser only. Nothing is sent to or stored on a server.
FAQ
What should lastmod contain?
Do I need changefreq and priority?
How many URLs can a sitemap contain?
Can I use non-ASCII characters in sitemap URLs?
Is what I paste sent anywhere?
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