Free tools for people who run websites
15 small tools that answer one question each. Free, with no sign-up.
Website
Check a site, its certificate and its schedules.
- SSL checkerWhen a certificate expires, who issued it, and whether browsers trust it.
- Cron expression explainerType a cron schedule, read it in plain words, see the next 5 runs.
- Uptime calculatorTurn an uptime percentage into allowed downtime per day, week, month and year.
- Website down checkerTest any site from our server: down for everyone, or just you?
DNS records
Read any record of a domain, live from public resolvers.
- DNS lookupEvery record of a domain in one table: A, AAAA, CNAME, MX, NS, TXT, SOA and CAA.
- A record lookupThe IPv4 address a domain points to, with its TTL.
- AAAA record lookupThe IPv6 address a domain points to, with its TTL.
- CNAME lookupThe name a subdomain is an alias of.
- NS lookupThe name servers that hold a domain's records.
- TXT lookupEvery TXT record of a domain: SPF, verification codes and more.
- SOA lookupA zone's primary server, serial number and timers, explained.
- CAA lookupWhich certificate authorities may issue certificates for a domain.
Find out where mail goes and whether it will be trusted.
Also free
A tool checks once. A monitor checks every minute.
PULSX watches your site, DNS, SSL certificate and cron jobs every 60 seconds and alerts you when one fails. Free for 20 monitors, with no card.