Help
How can we help?
Getting started
- Pick a tool from the home page. Most take one input: a domain, an IP, a URL or a MAC address.
- Nothing you look up is stored. Bookmark or share a result’s URL to run the check again later.
- Every tool also answers curl in plain text, and JSON with ?format=json. See the API reference.
Webmaster
SEO & meta tag checkerFetches a page like a search engine and shows its Google result and link preview, plus a checklist of what to fix: title, description, canonical, indexing, headings, images, sharing tags and structured data. robots.txt testerReads a site’s robots.txt and tells you whether a crawler (Googlebot, Bing, GPTBot, ClaudeBot…) may fetch a given URL, which line decides it, and what’s wrong with the file. Sitemap validatorFinds a site’s XML sitemap (through robots.txt or the usual locations) and checks it the way search engines do: format, size limits, URL problems, dates, and whether a sample of the listed pages actually loads.Web
HTTP headersShows the HTTP headers your browser sends, or fetches any URL and shows its response headers, redirect chain and a security-header check. SSL certificate checkChecks a site’s TLS certificate: whether it’s trusted, how many days are left, which names it covers, who issued it, and the chain.DNS & email
DNS lookupLooks up DNS records for a domain (A, AAAA, MX, TXT, NS, CAA and more), or does a reverse lookup for an IP address, through Cloudflare’s 1.1.1.1. DNS propagationAsks nine public DNS resolvers the same question and shows them side by side, so you can see which ones still have an old answer after a change. WHOIS / RDAPRegistration data for a domain, IP address or AS number over RDAP (the modern WHOIS): registrar, key dates, status, nameservers and abuse contact. Email healthChecks a domain’s email setup in one go: MX, SPF, DKIM, DMARC, MTA-STS, TLS-RPT and BIMI, with a pass/warn/fail summary.Nothing matches. Try the FAQ.