Free monitoring & DevOps tools

Check any domain's SSL certificate — issuer, expiry date, days remaining, certificate chain validity, protocol, and cipher.

Target query: "check SSL certificate expiry"

Look up domain registration details — registrar, registration date, expiry date, nameservers, status codes, and DNSSEC.

Target query: "when does my domain expire"

Query multiple global DNS resolvers simultaneously to check if your DNS changes have propagated. Supports A, AAAA, CNAME, MX, NS, TXT, SOA, and CAA records.

Target query: "DNS propagation checker"

Inspect any URL's HTTP response headers. See security headers (HSTS, CSP, X-Frame-Options), caching configuration, CORS policy, and server info.

Target query: "check HTTP headers security"

Build cron expressions with a visual editor. See human-readable descriptions, preview next run times, and copy for crontab, Kubernetes, or GitHub Actions.

Target query: "cron expression builder"

Generate professional status page updates for every phase of an incident — investigating, identified, monitoring, and resolved.

Target query: "incident response template"

Generate a structured postmortem document with timeline, root cause, contributing factors, and action items. Download as Markdown, HTML, or plain text.

Target query: "incident postmortem template"

Calculate allowed downtime from uptime SLAs and compare 99.9%, 99.99%, and 99.999% across day, week, month, and year.

Target query: "how much downtime is 99.99 uptime"