Asniher
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SSL certificate monitoring that catches failed renewals

Automatic renewal fails quietly: a changed DNS record, a firewall rule, a server still serving the old certificate. An Asniher SSL monitor connects to your host over TLS, inspects the certificate it presents and alerts while there is still time to fix it.

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What you get with SSL certificate monitoring

Expiry warnings on your terms

Set the warning threshold anywhere from 1 to 90 days. The monitor fails when fewer days remain, and the alert says how many.

Trust problems, not just dates

Self-signed certificates, wrong host names, missing intermediate certificates and expired certificates fail the check with the validation error.

The certificate your server presents

The check connects with SNI for the host name you enter, so it sees the certificate actually served for that name, not the one you think you installed.

Closes itself after renewal

Once the renewed certificate is served, the next check passes, the incident closes and a recovery alert goes out.

Set it up in a few minutes

  1. Step 1

    Add an SSL monitor

    Enter https:// and the host name. Add one monitor per host name: example.com and api.example.com can serve different certificates.

  2. Step 2

    Choose a threshold

    14 days for certificates that renew automatically, such as Let's Encrypt, which renews with 30 days left. 30 days or more for certificates you renew by hand.

  3. Step 3

    Pick an interval

    Certificates change rarely, so an hourly check is usually enough.

  4. Step 4

    Connect an alert channel

    Alerts go to your account email by default. Add Slack, Discord, Telegram or a webhook for the team.

Limits by plan

Every plan includes false-alarm protection, incident history and the status badge. Annual billing gives two months free.

Free · $0/mo

Uptime monitors (HTTP(S), keyword, SSL)
5
Shortest check interval
Every 5 minutes
Alert channels
Email, Slack, Discord

Pro · $2.99/mo

Uptime monitors (HTTP(S), keyword, SSL)
50
Shortest check interval
Every 1 minute
Alert channels
Email, Slack, Discord, Telegram, Webhook

Team · $9.99/mo

Uptime monitors (HTTP(S), keyword, SSL)
200
Shortest check interval
Every 30 seconds
Alert channels
Email, Slack, Discord, Telegram, Webhook

Good to know

  • SSL monitors share the uptime monitor allowance with HTTP(S) and keyword monitors.
  • URLs must start with https://. Each monitor checks the certificate for one host name.
  • An SSL monitor inspects the certificate only. Add an HTTP(S) monitor to check that the site itself responds.
  • Only public addresses can be checked. Private ranges such as 10.0.0.0/8, 192.168.0.0/16 and 127.0.0.1 are rejected; for internal services, use a heartbeat monitor and ping out from inside your network.

Common questions

How is this different from the free SSL checker?

The SSL checker inspects a certificate once, when you ask. An SSL monitor repeats the check on a schedule and alerts you, so a failed renewal is caught before visitors see a browser warning.

Do I need an SSL monitor if I already monitor the site over HTTPS?

An HTTP(S) monitor fails once the certificate has expired or is untrusted, because the TLS connection fails. An SSL monitor warns you days or weeks before expiry, while there is still time to renew.

What threshold should I use with Let's Encrypt?

14 days. Let's Encrypt clients renew with 30 days left, so an alert at 14 days means renewal has been failing for over two weeks.

Docs and free tools

Start monitoring in under five minutes

Free plan includes 5 monitors, 20 cron job heartbeats, 5-minute checks and a public status page. No card required.

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