Free SEO, performance, and debugging tools. Built by developers, for developers.
Check if a website is online or offline in real time.
Verify SSL certificate validity, expiry, and security headers.
Validate robots.txt, check crawl rules, sitemaps, and bot access.
Test LCP, INP, CLS and other Core Web Vitals scores.
Check if your page is mobile-friendly per Google guidelines.
Run Lighthouse performance audit and get optimization scores.
Look up domain registration details, registrar, and expiry date.
Check how old a domain is and when it was registered.
Query A, AAAA, MX, TXT, NS, and CNAME records for any domain.
Find the IP address(es) a domain resolves to.
Check if a domain is available for registration.
Check SPF, DKIM, DMARC, and DNSSEC records for a domain.
Full domain health check: DNS, SSL, email, and security.
Check if CSS, JS, and HTML files are properly minified.
Check if images are compressed and use modern formats.
Detect CMS, frameworks, analytics, and other technologies.
View rendered HTML source from any URL or paste code.
Check if a page uses server-side or client-side rendering.
Trace full redirect chains and detect loops.
Minify CSS and JavaScript code to reduce file sizes.
Minify HTML code to reduce file size.
Generate a robots.txt file with common rules for search engines.
Generate Open Graph and Twitter Card meta tags.