Skip to content
Utiloom

XML Sitemap Validator

Validate bounded URL sets and sitemap indexes locally for UTF-8 XML, the protocol namespace, URLs, W3C dates, duplicates, optional hints, and core size limits.

LocalNo sitemap retention

Reviewed July 13, 2026

Guide, examples, and validation Show

About this tool

Create bounded static evidence for a sitemap file before deployment or submission without turning XML structure into a live URL, indexing, or ownership claim.

XML Sitemap Validator processes a bounded URL set or sitemap index locally and checks UTF-8 XML, the exact sitemap protocol namespace, required loc values, real W3C calendar dates, normalized duplicates, optional fields, and core entry and byte limits.

  • Parses pasted XML or an opened UTF-8 file in a disposable browser worker and rejects DTD or entity declarations, invalid XML declarations, malformed roots, and an incorrect default protocol namespace.
  • Validates required absolute HTTP(S) loc values, normalized duplicates, strict W3C lastmod dates, case-sensitive changefreq values, decimal priorities, host and protocol review signals, and optional deployment context.
  • Enforces the 50 MiB uncompressed and 50,000-entry protocol limits, caps returned evidence, and exports a versioned JSON report without repeating the full parsed document.

How to use Sitemap Validator

Paste up to 5,000,000 characters or open an XML file up to 50 MiB, optionally enter the deployed sitemap URL for host and directory context, then run validation. Review blocking protocol errors separately from deployment warnings and download the bounded JSON evidence if needed.

When this tool is useful

  • Validate a generated sitemap.xml before submitting it in Google Search Console.
  • QA CMS or build-step sitemap output after a routing or localization change.
  • Check duplicate loc entries, malformed lastmod values, or protocol mistakes in client sitemaps.
  • Review sitemap indexes before large content launches or localization rollouts.

Practical tips

  • Validate the file structure first, then separately crawl important URLs and inspect response, canonical, and robots evidence.
  • Keep each sitemap within 50,000 entries and 50 MiB (52,428,800 bytes) uncompressed.
  • Use sitemap indexes when your site grows beyond a single clean sitemap file.
  • Google ignores changefreq and priority; include them only when another consumer needs those optional protocol hints.

Examples you can test

Load an example, compare the result with the expected output, then replace it with your own input.

Validate a small sitemap

Example input

<urlset xmlns="http://www.sitemaps.org/schemas/sitemap/0.9"><url><loc>https://example.com/</loc><lastmod>2026-03-11</lastmod></url></urlset>

Expected output

URL set protocol structure passes

The exact default namespace and one absolute loc are required; no live URL request is made.

Reject an impossible date

Example input

<lastmod>2026-02-30</lastmod>

Expected output

Blocking invalid-lastmod finding

Validation checks real Gregorian calendar dates instead of relying on permissive Date.parse behavior.

Review a mixed-protocol file

Example input

One HTTPS loc and one HTTP loc

Expected output

HTTP and mixed-protocol review warnings

HTTP is permitted by the protocol, so this is a canonical deployment review rather than a syntax error.

Validation checklist

  • Use the exact sitemap protocol default namespace and one absolute HTTP(S) loc per entry.
  • Encode the file as UTF-8 and XML-escape ampersands and other reserved characters.
  • Review live status, redirects, canonical URLs, robots directives, ownership, and indexability outside this static file check.

Frequently asked questions

Does this tool support sitemap indexes as well as normal sitemaps?

Yes. It validates the core structure of both urlset and sitemapindex documents and checks the required loc value in each entry.

Can this replace a live crawl test?

No. It does not fetch URL responses, follow redirects, inspect canonical or robots directives, prove ownership, submit the sitemap, or confirm indexing.

Does the validator check for URLs that use HTTP instead of HTTPS?

Yes. HTTP entries and mixed HTTP/HTTPS sets are review warnings because the sitemap protocol permits HTTP, while the intended canonical protocol depends on the deployed site.

What is the maximum number of URLs the validator can process in a single sitemap?

It enforces 50,000 entries and 50 MiB of uncompressed UTF-8 XML. Pasted input is capped at 5,000,000 characters; larger valid files can be opened directly up to 50 MiB.

Does it validate lastmod date formats?

Yes. It validates the W3C Datetime lexical form and real calendar dates, rejects malformed values, and reports future values for review.

Related tools

Keep the workflow moving

Continue with tools that handle a related input, output, or validation step.

SEO

AI Crawler Policy Generator

Generate robots.txt rules for AI crawlers and search bots.

Local
SEO

Faceted Navigation Indexability Checker

Review faceted URL policy evidence locally.

Local
SEO

FAQ Schema Generator

Build and validate FAQPage JSON-LD locally.

Local
SEO

Internal Link Checker

Inspect authored links and page-level inventory coverage.

Local