Free webmaster and SEO tools that run in your browser
Check robots.txt rules, validate sitemaps, feeds, hreflang and structured data, preview how a page looks in search and social, read HTTP headers and crawler logs. Nothing you paste leaves your device.
Crawling
- robots.txt Tester
Test whether Googlebot, Bingbot or AI crawlers may fetch a URL, and see which rule decides.
- robots.txt Generator
Build a correct robots.txt: block folders, add sitemaps, opt out of AI training crawlers.
- XML Sitemap Validator
Validate a sitemap or sitemap index against the protocol and Google's rules; build one from a URL list.
On-page
- Meta Tag & Open Graph Checker
Paste a page's HTML to preview its Google result and social cards and list tag problems.
- Meta Tag & Open Graph Generator
Fill in a form, get title, description, canonical, Open Graph and Twitter card tags with live previews.
- JSON-LD Structured Data Checker
Find JSON syntax errors and missing Google-required properties in schema.org JSON-LD.
Server
- HTTP Header & Redirect Checker
Paste curl output to explain a redirect chain, status codes, caching and security headers.
- Crawler Log Analyzer
Open an access log to see what Googlebot and other crawlers fetched, which errors they hit, and fake bots.
International
- hreflang Checker & Generator
Validate hreflang codes, self-references and return links across pages, or generate the tags.
Content
- RSS & Atom Feed Validator
Validate RSS 2.0, Atom and JSON Feed: required elements, dates, GUIDs, enclosures; preview items.
- UTM Builder & URL Parser
Build campaign URLs that GA4 attributes correctly, in bulk; take any URL apart into its pieces.
Why these tools
Each tool does one job and shows its reasoning. The robots.txt tester tells you which line decided the result; the sitemap validator names the entry and the rule it breaks; the header checker explains every status code and cache directive in plain words. The explanations under each tool are written from the specifications (RFC 9309 for robots.txt, the sitemaps.org protocol, RFC 9110 and RFC 9111 for HTTP, the RSS 2.0 and Atom specs) and from Google's own Search Central documentation, with links to them.
Everything runs as JavaScript on this page. There is no account, no upload and no server-side processing, so you can safely paste private staging URLs, server logs or unpublished markup. A browser cannot fetch other websites for you (browsers block that for security), so each tool works on text you paste or a file you choose. Where a job needs fetching thousands of live pages, the tool page says so and points to a hosted tool that can.