SSL certificate monitoring
An expired certificate takes a site fully offline for every visitor at once, and it always happens at the worst time. PingDog connects over TLS on your schedule, reads the certificate, and warns you well before it lapses.
What PingDog checks
- Certificate validity — is the presented chain currently valid
- Days remaining until expiry
- Early warning as the expiry date approaches, so a renewal never sneaks up on you
TLS certificates are the classic silent failure: everything is fine until, at 00:00 UTC on the expiry date, every browser refuses the connection. Auto-renewal helps, but auto-renewal also fails silently — a hook that didn't fire, a DNS challenge that broke. An independent watch on the actual served certificate is the backstop.
PingDog reads the certificate the way a browser would, from outside your infrastructure, so it sees exactly what your users see — including a renewal that updated the config but never reloaded the server.
Anonymous, pay-per-check
Like everything on PingDog, this check needs no account: your key is the account, you pay once at $0.0005 per delivered check in USDC on Base, and nothing renews. A real free tier runs up to 3 monitors at a 5 minutes interval with no payment at all. See how pricing works.
Frequently asked
How far in advance am I warned about expiry?
PingDog surfaces the days remaining on each check and alerts as the expiry date approaches, so you have time to renew before a certificate lapses.
Does it check the certificate actually being served?
Yes. It connects over TLS to the live endpoint and reads the presented certificate — so it catches the case where a renewal updated the files but the running server is still serving the old one.