Free Network & Security Tools

Look up DNS records (A, AAAA, MX, TXT, NS, SOA) for any domain online. Fast, free, no signup.

Look up WHOIS/RDAP registration data for a domain or IP: registrar, dates, name servers, network owner.

Scan a host for common open TCP ports and the services behind them. Fast online port checker.

Check a site's SSL/TLS certificate: issuer, validity dates, expiry, and subject. Free online SSL checker.

Check a URL's HTTP response headers, including security headers like HSTS, CSP, X-Frame-Options.

Test whether a host answers on a specific TCP port and how fast. Free online TCP ping.

Trace the network path to a host and see per-hop latency and packet loss with MTR online.

See your public IP address, approximate location, ISP and network (ASN). Instant IP lookup.

Look up the organisation, network range and abuse contact behind any public IP address.

Check a domain's SOA record: primary name server, admin contact, serial number and zone timers.

Calculate network address, broadcast, netmask, wildcard mask and usable host range from an IPv4 CIDR. Runs entirely in your browser.

Decode a JWT's header and payload instantly in your browser. No signature verification, nothing ever sent to a server.

Encode text to Base64 or decode Base64 back to text, instantly in your browser. UTF-8 safe, no signup.

Generate SHA-1, SHA-256, SHA-384 and SHA-512 hashes of any text using the browser's Web Crypto API. Nothing sent to a server.