Free tools

Tools for domains, DNS & uptime

Handy DNS, email, network and monitoring utilities — free, no signup required.

Domain Health Check

Type a domain and see in about ten seconds whether the site is up, the certificate is trusted, the DNS is sound and the email records are in place.

Check what receivers see, then generate the record that fixes it.

Check a domain’s SPF record and how close it is to the ten-lookup limit.

Check a domain’s DMARC policy and whether it actually protects anything.

Check a domain’s mail servers — and whether mail can actually reach them.

Add a sender to your SPF record without breaking the one you have.

Read a domain’s mail setup and get the DMARC record it should publish next.

Whether it answers, and whether browsers trust the certificate.

Check whether a website is up or down, right now, from the edge.

Verify a domain serves a valid, trusted HTTPS certificate.

What your nameservers publish, what the world has cached, and when the last old copy expires.

See whether a DNS change has landed everywhere, and exactly when the last cache lets go.

See every common DNS record for a domain, and what they say together.

Calculators for networks and uptime targets, no domain needed.

Calculate network, broadcast, host range and usable hosts from a CIDR.

Turn an uptime SLA percentage into allowed downtime per day, month and year.

In the dashboard these stop being one-off lookups: records watched, certificates tracked, and a message when something changes.

Free plan · No credit card required · Set up in minutes