What is a Sitemap Validator?
A sitemap validator is a diagnostic tool that checks your XML sitemap for syntax errors, structural issues, and SEO compliance. It verifies that your sitemap follows the sitemaps.org protocol and helps you identify problems that could prevent search engines from properly discovering and indexing your pages.
Validate XML structure, check URL formats, detect duplicate entries, verify file size and URL limits, and ensure proper namespace declarations. Our validator provides instant feedback on errors, warnings, and optimization opportunities.
Essential for SEO professionals, webmasters, and developers who need to ensure their sitemaps are error-free before submitting to Google Search Console, Bing Webmaster Tools, and other search engines.
Why Validate Your Sitemap?
A broken sitemap means search engines can't properly crawl your site. Syntax errors, invalid URLs, and protocol violations cause search engines to ignore your sitemap entirely, leaving your pages undiscovered and unindexed.
Common sitemap errors include missing XML declarations, incorrect namespaces, duplicate URLs, URLs exceeding the 50,000 limit, file sizes over 50MB, invalid date formats, and malformed URL entries. Each error reduces your sitemap's effectiveness and can hurt your SEO performance.
Our sitemap validator catches these issues before you submit to search engines. It checks XML syntax, validates every URL, detects duplicates, verifies size limits, and provides actionable recommendations. Fix errors early to ensure maximum crawl coverage and indexing efficiency.
Key Features
XML Syntax Validation
Verify XML structure, check for proper declarations, validate closing tags, and ensure well-formed XML that search engines can parse.
URL Format Checking
Validate every URL in your sitemap. Check for invalid protocols, unescaped characters, spaces, and malformed URLs that could cause crawl errors.
Duplicate Detection
Identify duplicate URLs in your sitemap. Each URL should appear only once to avoid wasting crawl budget and sending mixed signals.
Size Limit Validation
Check that your sitemap doesn't exceed the 50MB size limit or 50,000 URL limit. Get warnings when approaching these thresholds.
Namespace Verification
Ensure your sitemap uses the correct XML namespace (http://www.sitemaps.org/schemas/sitemap/0.9) required by the protocol.
Date and Attribute Validation
Validate lastmod dates (ISO 8601 format), check changefreq values, verify priority ranges (0.0-1.0), and catch future dates.
How It Works
- Enter the full URL of your XML sitemap (e.g., https://example.com/sitemap.xml).
- Click "Validate Sitemap" to fetch and analyze the file. The validator checks syntax, structure, and content.
- Review errors (critical issues that must be fixed), warnings (issues that should be addressed), and info messages.
- Check the statistics panel to see total URLs, file size, duplicates, and URLs with issues.
- Examine individual URL issues like invalid formats, bad dates, or incorrect attributes.
- Fix identified problems in your sitemap, regenerate it, and re-validate to confirm all issues are resolved.
Common Sitemap Errors
✕Missing XML Declaration
Your sitemap must start with <?xml version="1.0" encoding="UTF-8"?>
Fix: Add the XML declaration as the first line of your sitemap file.
✕Invalid Namespace
The <urlset> tag must include: xmlns="http://www.sitemaps.org/schemas/sitemap/0.9"
Fix: Use the correct namespace URL in your urlset or sitemapindex tag.
✕Duplicate URLs
Each URL should appear only once in your sitemap. Duplicates waste crawl budget and can confuse search engines.
Fix: Remove duplicate entries. Check your sitemap generator settings if duplicates appear automatically.
✕Exceeding URL Limit
Sitemaps cannot contain more than 50,000 URLs. Sites with more URLs need to use a sitemap index file.
Fix: Split your sitemap into multiple files and create a sitemap index that references them.
âš Invalid lastmod Format
The lastmod field must use ISO 8601 format: YYYY-MM-DD or YYYY-MM-DDThh:mm:ss+00:00
Fix: Use proper date formatting. Example: 2024-01-15 or 2024-01-15T10:30:00+00:00
âš Invalid URL Format
URLs must use http:// or https:// protocol, contain no spaces, and properly escape special characters like & as &
Fix: Ensure all URLs are absolute, properly formatted, and use valid protocols.
Sitemap Best Practices
- Include only canonical URLs with 200 status codes - no redirects, 404s, or blocked pages
- Keep sitemaps under 50,000 URLs and 50MB; use sitemap index files for larger sites
- Update lastmod dates when content actually changes to signal freshness to search engines
- Use consistent URL formats (all http or all https, with or without www)
- Submit sitemaps to Google Search Console and Bing Webmaster Tools
- Reference your sitemap in robots.txt: Sitemap: https://example.com/sitemap.xml
- Compress large sitemaps with gzip to reduce bandwidth (sitemap.xml.gz)
- Regenerate sitemaps when adding or removing significant content
- Use sitemap index files to organize sitemaps by content type or date
- Validate sitemaps before submitting to catch errors early
Sitemap Technical Limits
50,000 URLs
Maximum number of URLs allowed in a single sitemap file. If you have more, use a sitemap index to reference multiple sitemap files.
50 MB
Maximum uncompressed file size. Large sitemaps should be split into smaller files or compressed with gzip to reduce size.
1,000 Sitemaps
Maximum number of sitemap files that can be referenced in a single sitemap index file.
UTF-8 Encoding
All sitemap files must use UTF-8 character encoding and must be properly escaped for special characters.
Frequently Asked Questions
What is a sitemap validator?+
A sitemap validator is a tool that checks your XML sitemap for errors, validates the structure, verifies URLs, and ensures compliance with sitemap protocol standards. It helps identify issues that could prevent search engines from properly crawling your site.
What are common sitemap errors?+
Common sitemap errors include: invalid XML syntax, wrong namespace, URLs exceeding 50,000 limit, file size over 50MB, duplicate URLs, invalid URL formats, incorrect lastmod dates, and missing required elements like <loc> tags.
How many URLs can a sitemap contain?+
A single XML sitemap file can contain a maximum of 50,000 URLs and must not exceed 50MB in uncompressed size. If you have more URLs, use a sitemap index file to reference multiple sitemaps.
What is the correct XML namespace for sitemaps?+
The correct namespace is: xmlns="http://www.sitemaps.org/schemas/sitemap/0.9". This should be included in the <urlset> or <sitemapindex> tag.
How do I fix duplicate URLs in my sitemap?+
Remove duplicate entries from your sitemap. Each URL should appear only once. If your sitemap is auto-generated, check your CMS or sitemap generator settings to prevent duplicates from being created.
Ready to validate your sitemap? Use the XML sitemap validator above to check for errors, verify compliance, and ensure search engines can properly crawl and index your pages.