TLS certificate monitoring

When to use TLS#

Use TLS monitoring for an HTTPS hostname whose certificate validity and expiry are operationally important. It complements Uptime; it does not replace normal website availability checks.

Create the monitor#

1. Open Monitors and click New Monitor.
2. Select TLS.
3. Enter a friendly label.
4. Enter an HTTPS URL, normally the public homepage or intended hostname.
5. Create the monitor.

TLS uses a fixed 12-hour cadence. It is not a one-minute web probe.

Expected result#

A healthy result confirms that usable certificate evidence was obtained and shows expiry context. Warning/Expiring indicates attention is needed before expiry. Unknown or source-limited means Watchfox could not establish a definitive state from the available source and should be investigated rather than treated as a confirmed outage.

Common mistakes#

• Entering an HTTP-only URL instead of the intended HTTPS hostname.
• Assuming TLS Up proves the application itself is available.
• Treating a fixed lower cadence as a scheduler failure.
• Ignoring hostname differences such as www versus the apex domain.
• Interpreting Unknown as certificate expiry without checking the evidence.