A sitemap checker is a technical SEO utility that inspects and validates XML sitemaps against official search engine standards. Validating your sitemap ensures it adheres to the official Sitemaps.org 0.9 protocol, preventing syntax corruptions, broken URLs, or invalid lastmod dates from obstructing Googlebot and Bingbot crawlability.

The official Sitemaps.org protocol strictly limits individual sitemap files to a maximum of 50,000 URLs and an uncompressed file size of 50MB. If your website exceeds either threshold, you must partition your URLs across multiple sitemaps and reference them inside a parent <sitemapindex> file.

The most common syntax error is unescaped entity characters in URL query strings, particularly the ampersand (&) instead of &amp;, or unclosed XML tags. Our Auto-Fix tool detects unescaped entities and automatically transforms raw ampersands into valid XML entities while inserting the required Sitemaps.org namespace and UTF-8 declarations.

The <lastmod> tag must follow the W3C Datetime format, which is a subset of ISO 8601. Accepted formats include YYYY-MM-DD (e.g., 2026-10-24) or full timestamps with timezone offsets like YYYY-MM-DDThh:mm:ss+00:00. Non-standard dates (such as MM/DD/YYYY) are flagged as invalid and will be ignored by Google.

Google requires all <loc> tags in an XML sitemap to be absolute, fully-qualified URLs beginning with https:// or http://. Relative paths (like /about) cannot be resolved accurately. Duplicate URLs waste search engine crawl budgets and indicate canonicalization configuration errors on your CMS.

Pressing Alt+P (or clicking the Smart Paste button) reads your clipboard text. If the clipboard contains a web URL ending in .xml or starting with http://, it routes to the URL Fetcher mode and initiates a live inspection. If the clipboard contains raw XML markup, it automatically populates the XML Editor and validates your markup client-side with zero latency.

Yes! Our parser detects and audits official Google namespace extensions including image:image, video:video, news:news, and xhtml:link rel='alternate' hreflang. It verifies that media locations and language alternates are properly structured without triggering false syntax errors.

Once your sitemap passes validation with 0 critical errors, click on our integrated Search Engine Submission & Ping Hub links. They guide you directly to the sitemaps submission dashboard in Google Search Console (search.google.com/search-console/sitemaps) and Bing Webmaster Tools (bing.com/webmasters/sitemaps) for instant indexation requests.