Network Tools

Look up how a domain, address or server is configured on the internet

When a site is slow, an email bounces, or a certificate warning appears, the answer usually sits in public records: DNS, WHOIS, TLS certificates, HTTP headers or blocklists. The lookups in this category query those sources and present the results in a readable form, so you can diagnose without opening a terminal.

System administrators and developers use them during migrations and outages. DNS, propagation and reverse IP lookups show where a name points. The SPF, DKIM, DMARC and MX tools explain why mail lands in spam. The subnet calculator handles address planning, and the ASN lookup identifies who operates a network.

Because most of these lookups reach out to remote servers, results reflect public information as seen from our side, not from inside your own network. DNS changes also take time to spread, so a value that looks wrong right after an edit may simply not have propagated yet. Wait a while and query again before you assume the change failed.

Common questions

Why do DNS results differ between tools?

DNS answers are cached at many resolvers for as long as each record's time-to-live allows. After a change, some resolvers show the new value while others still serve the old one until their cache expires.

What do SPF, DKIM and DMARC each do?

SPF lists which servers may send mail for your domain, DKIM adds a cryptographic signature to each message, and DMARC tells receivers what to do when those checks fail. Most mailbox providers now expect all three.

Does the ping tool work like the command-line ping?

It tests whether a host responds, but it runs from a web server and uses web-reachable methods rather than raw network packets. Treat the timings as a rough signal instead of a precise latency measurement.