Free network tools

Every tool runs live from our London server the moment you press the button — no queues, no accounts, no results pulled from a stale database. Each one also explains what the numbers mean, because a wall of output you cannot interpret is not a diagnosis.

Website status checker

Run a live HTTP request against any website and see status code, load time, first byte, redirects, server software and page size.

Ping test

Send real ICMP pings to any host and read back minimum, average and maximum round-trip time plus packet loss.

DNS lookup

Query every common DNS record type for a domain, with TTLs, straight from an authoritative resolver.

SSL certificate checker

Inspect the live TLS certificate on any host: who issued it, when it expires, which names it covers and which protocol was negotiated.

HTTP header & security check

See the raw HTTP response headers a site sends, and get a graded report on HSTS, CSP, X-Frame-Options and the rest.

Open port checker

Test whether common TCP ports — SSH, SMTP, HTTPS, MySQL and more — are reachable on a host from the public internet.

WHOIS lookup

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

IP address lookup

Find out which network an IP address belongs to, where it is routed, its ASN and its reverse DNS name.

Email deliverability check

Check whether a domain is set up to send email that arrives: mail servers, SPF record, DKIM selectors and DMARC policy.

Blacklist check

Query ten major DNS blocklists — Spamhaus, SpamCop, Barracuda and others — to see whether a mail server IP is listed.

Redirect checker

Trace every hop a URL takes, with status codes and timings, so you can find redirect loops and needless extra hops.

Response time test

Break a request into DNS, TCP connect, TLS handshake and time to first byte, so you know which stage is slow.

Which tool should I use?

"My site is down." Start with the website status checker. It runs the HTTP request, the ping and the certificate check together and names the failure.

"My site is slow." Use the response time test to see whether the delay is network, TLS or your application, then the ping test to rule out the network entirely.

"I changed DNS and something broke." The DNS lookup shows what the world actually sees, with TTLs telling you how long the old answer can linger.

"Visitors get a security warning." The SSL checker reads the live certificate: expiry, hostname coverage and whether the chain is complete.

"Our emails go to spam." Run the email deliverability check for SPF, DKIM and DMARC, then the blacklist check on your sending IP.

"Is this server exposed?" The port checker tests from outside your network, which is the only view that tells you what an attacker sees.