Free tools
Calculators and references for the questions that come up while setting up monitoring or reviewing an incident. No account needed.
The SLA, downtime-cost and cron pages run in your browser. The rest are references that explain what to look for and how to read a result.
Cron Expression Generator
Free cron expression generator: build a readable cron schedule from plain requirements, then pair the job with an owner and a heartbeat so a missed run alerts.
Cron Expression Tester
Free cron expression tester: see the next run times for any cron schedule — across time zones and daylight saving — before you wire up heartbeat monitoring.
DNS Lookup
Free DNS lookup: inspect A, AAAA, CNAME, and other records for a hostname before you point monitoring at it, so a stale record never keeps a check green on the wrong host.
Downtime Cost Calculator
Free downtime cost calculator: estimate the revenue, support, and churn cost of an outage so you can decide where faster monitoring and redundancy actually pay off.
HTTP Headers Inspector
Free HTTP headers inspector: review response headers — caching, redirects, content type, and security headers — to debug behavior a status code alone hides.
HTTP Status Code Lookup
Free HTTP status code lookup: what every 2xx, 3xx, 4xx, and 5xx code means, and how to decide which codes a monitor should treat as healthy or as a failure.
Ping Tool
Free ping tool: check whether a host is reachable over ICMP — and understand why a green ping is only the floor, not proof that the service on it works.
SSL Certificate Checker
Free SSL certificate checker: inspect a site's TLS certificate expiry, issuer, and covered hostnames — then set a continuous check so a renewal never lapses.
TLS Version Checker
Free TLS version checker: see which TLS protocol versions a host supports, to catch deprecated TLS 1.0/1.1 during hardening and compliance reviews.
Uptime SLA Calculator
Free uptime SLA calculator: convert an uptime percentage into allowed monthly and yearly downtime, and see what a tighter SLA really demands of your operations.
Looking for something else? Browse all features or see pricing.