Is my sitemap uploaded?

No. Parsing and validation happen in your browser.

What's a common bug it catches?

Invalid lastmod dates (e.g., 2024-13-32 or non-W3C-datetime strings). Most generators get the format right, but custom-rolled exporters often don't.

Does it follow sitemap index references?

It validates the current document. For an index file, paste each child sitemap separately to validate them, since trydevtools doesn't fetch external URLs from the validator.

What URL count triggers a warning?

Sitemaps over 50,000 URLs or 50 MB uncompressed exceed the spec and should be split. The validator flags this as an error.

sitemap · validator · sitemaps.org spec

Validate a sitemap.xml

Parse and check any sitemap against the sitemaps.org spec — namespace, root element, entry counts, loc validity, file size.

Sitemap Validator

Checks

total

Passed

Failed

issues

Status

invalid

spec

input · sitemap.xml

output · checks

✗ ParseDOMParser is not defined

Quick Start

How to validate a sitemap

The sitemaps.org spec is strict about root element, namespace, and URL counts. This tool flags the most common breakage points.

01
Paste sitemap
Drop in the raw XML — works for both urlset and sitemapindex.
Lookups reference the IANA registries (MIME, HTTP status, TLDs) bundled at build time — no live network calls, no rate limits, no leaked queries.
inputIANAregistryofflinelive
input · queryxml · IANA
```
<urlset .../>
```
loaded · IANA bundlespec · ready
02
Parse and inspect
DOMParser checks for well-formed XML and the right namespace.
Builders emit canonical syntax per the relevant RFC (9110 for HTTP, 5322 for headers, 3986 for URLs) so the output passes spec-compliant parsers.
parseRFC 9110canonicalspec-compliantlive
parse · optionsxml · live
```
DOMParser
```
options applied · livecanonical
03
Audit entries
Each <loc> in the first 50 is checked with the URL constructor.
Validation flags common pitfalls — uppercase header names, smart quotes inside Content-Type, missing ;charset=utf-8 — before they bite production.
auditvalidationlintpitfallslive
loc · looked upurl · ready
```
new URL(loc)
```
result · livevalidated
04
Read the report
Each check pass/fails with detail you can paste into a PR comment.
Copy writes the snippet directly into your clipboard; downloads emit the right extension and MIME so curl/httpie pick them up correctly.
reportclipboardMIME-correctblobcurl-ready
ok · copiedreport · done
```
✓ all checks
```
shipped · ready to shipsuccess

Pro tips

Web-spec details that bite later

Idempotency saves retries

POST/PUT/DELETE should be safely retried. Use idempotency keys and return the same response on duplicate requests.

Match RFC 9110 status codes

Don’t invent codes. 422 for validation errors, 409 for conflicts, 429 for rate limits. Standard codes work with off-the-shelf clients.

Set <code>Cache-Control</code> deliberately

Default browser caching is conservative. Use max-age + stale-while-revalidate for hot endpoints.

Validate Open Graph in dev

OG tags break silently. Use a previewer like OG Generator + Facebook’s debugger before launch.

CORS is a server concern

The browser sends the preflight; the server decides. Wildcard origins disable credentials — be explicit.

MIME drives behaviour

Servers must send the right Content-Type. Browsers sniff but the spec says they shouldn’t — be explicit to avoid surprises.

Use Cases

When to validate sitemaps

Pre-deploy, post-migration, large catalog QA.

Pre-deploy QA

Catch a malformed XML before Google rejects it. Bundled from IANA registries at build time — no live network call, no rate limit, no leaked queries. The MIME, TLD, and status-code tables are baked in so the tool works offline once loaded.

spec-compliant

Migration audit

Sanity-check the new sitemap matches your URL structure. Output is canonical per the relevant RFC (9110 for HTTP, 5322 for headers, 3986 for URLs), so spec-compliant parsers accept it as-is. Cross-browser and cross-library behaviour stays consistent.

offline

Catalog growth

Confirm you're still within the 50k / 50 MB limits. Pairs with the curl-to-fetch converter for end-to-end test stubs — copy the curl from DevTools, paste, get an idiomatic fetch() body. Drop into Playwright/Vitest fixtures without manual translation.

IANA-backed

CI checks

Drop this into a pre-deploy gate to refuse broken sitemaps. Catches common pitfalls (uppercase header names, smart quotes inside Content-Type, missing ;charset=utf-8) before they bite production. Validation flags rather than auto-corrects so you stay in control.

RFC-aligned

Vendor sitemaps

Verify external sitemap output (e.g. CMS plugins). Validation runs as you type — copy only when the output is shaped correctly. The output drops directly into nginx, Apache, or CDN configs without re-formatting or re-quoting.

production-grade

Multilingual hreflang

Quick smoke test before submitting to Search Console. Same input plus same options always produces identical canonical output, so the tool is safe to embed in CI scripts that diff against expected configs.

i18n

FAQ

Frequently asked questions

Does it check every URL?

It validates the first 50 <loc> entries via the URL constructor — enough to spot structural issues quickly.

Will it follow the URLs?

No. Validation is offline — it never fetches your URLs.

What about sitemap indexes?

Yes — files with <sitemapindex> are recognized and entries counted as <sitemap> nodes.

Does it check XSD schema?

It enforces the namespace and structure; full XSD validation would require the schema fetch.

Does it run locally?

Yes. Everything is parsed in your browser — no upload.

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