IP, headers and cron.
Understand any cron expression in plain English and preview its next run times — 100% in your browser.
Look up and explain a domain's DMARC record — policy, reporting and alignment — on our server.
Look up a domain's DNS records — A, AAAA, MX, TXT, NS, CNAME, SOA and CAA — with TTLs.
Resolve a domain to its IPv4 (A) and IPv6 (AAAA) addresses — resolved on our server.
Open a .har file to see every request, status, size, timing and a waterfall — 100% in your browser.
Search and browse every HTTP status code with plain-English meanings — 100% in your browser.
Measure your real download, upload, ping and jitter against Cloudflare's global network — right in your browser.
Calculate network, broadcast, host range and subnet mask from an IPv4 CIDR — 100% in your browser.
Convert an IPv4 address to its IPv6 forms — mapped, compatible, 6to4 and expanded.
Press any key to see its JavaScript event.key, event.code and keyCode — 100% in your browser.
Find a domain's MX (mail server) records with their priorities — resolved live on our server.
Look up and explain a domain's SPF record — every mechanism and the final policy — on our server.
Break a URL into protocol, host, path, query and fragment — 100% in your browser.
Look up a domain's registrar, creation and expiry dates, name servers and status — via RDAP.
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