Domain tools

Who a domain is registered through, when it was created and when it needs renewing.

Look up domain registration data: who it is registered through, when it was created, when it expires and its nameservers.

Website checks Network tools DNS tools Security & TLS Email tools All tools

Reference

Look something up without running a check.

What 301, 403, 502 and the rest actually mean, and how to fix them.

What listens on each port and whether it should ever face the internet.

ERR_CONNECTION_REFUSED, NXDOMAIN, SSL errors — decoded.

A, MX, TXT, CNAME and friends, with real examples.

Subnet, cron, base64, JWT, hashes — private, in your browser.