CertSentry

CertSentry keeps watch over your certificates, domains, DNS and uptime, and warns you days before anything breaks. It opens real TLS connections, tracks domain registration expiry via RDAP, snapshots DNS records daily, and checks uptime from multiple regions. Alerts are delivered via email, Slack, Telegram, Discord, and webhooks. It also offers public status pages, Certificate Transparency monitoring, DMARC parsing, TCP port checks, and heartbeat monitoring.

• SSL certificate expiry monitoring (real TLS connection)
• Domain registration expiry tracking (RDAP with WHOIS fallback)
• DNS record change detection (A, AAAA, MX, NS, CNAME, TXT)
• Uptime monitoring from multiple regions (N. America, Europe, Asia)
• Alert thresholds: 30, 14, 7, 3, 1 days before expiry
• Two-region, two-consecutive-check outage confirmation
• Certificate Transparency alerts
• TCP port checks
• Heartbeat monitoring for cron jobs, backups, deploys
• DMARC report parsing
• Public status pages with certificate and domain health
• Shared workspaces with role-based access
• Environment labels (production/staging)
• Monitor client domains without ownership
• REST API with scoped keys
• Daily uptime stats with p50/p95 latency
• Declarative monitor sync from repo with dry-run
• Data export and deletion

Free personal workspace forever. Paid plans start at $5/mo (Starter), $12/mo (Pro), $50/mo (Agency). Annual billing saves ~2 months.