Uptime Kuma is a free, open-source (MIT) uptime monitor that you install and run yourself. It reads the certificate on its HTTPS checks and can alert before it expires. CertAvert is a hosted service that only watches certificates and domain names.
| CertAvert | Uptime Kuma | |
|---|---|---|
| Main product | Certificate and domain monitor | Uptime monitor |
| How it runs | Hosted, nothing to install | Self-hosted (Docker or Node.js); you keep it running and updated |
| Free | 15 domains | Free and open source |
| Paid plans | Starter 25, $50 a year; Plus 50, $100 a year; Pro 100, $150 a year (domains) | None; you pay for your own server |
| Billing | Yearly | None |
| Users per account | 1 | Not found |
| How often it checks | Twice a day | You set it, down to 20 seconds |
| Expiry alert days | 30 and on expiry (Free); 30, 14, 7 and on expiry (Starter); your own days (Plus, Pro) | Set once for all monitors, not per monitor |
| Short-lived certificates | Alerts at a quarter of the lifetime (under 80 days) | Not built (requested) |
| Ports other than 443 | Any port | HTTPS addresses only; TLS on TCP monitors removed in 2.5.8 |
| Untrusted certificate or wrong name | Shown with the reason; emailed on paid plans | The check fails, unless "Ignore TLS/SSL errors" is on (which also stops expiry alerts) |
| Chain check (missing intermediates) | Yes | Not found |
| Revocation check | Yes OCSP or CRL | Not found |
| Renewal window (ARI) | Yes | Not found |
| Post-quantum key exchange | Yes | Not found |
| Certificate change alerts | Shown on every plan; emailed on paid plans | Not found |
| Certificate Transparency logs | Lists other names under your domains; no alert for new ones | Not found |
| Domain name expiry | Registration dates on every plan; reminder emails on paid plans | Yes |
| Alert channels | Email, Slack, Discord, Teams | 90+ (email, Slack, Discord, Telegram, Teams, webhooks…) |
| API | No | Push API |
| Status pages | No | Yes |
| Internal certificates | No the free certavert-scan runs on your own network | Yes anything your server can reach |
| Audit report | Pro (PDF and CSV, checked at /verify) | Not found |
"Not found": we couldn't find it on Uptime Kuma's pages, which doesn't mean it isn't there. Uptime Kuma is a trademark of its owner; CertAvert isn't affiliated with it.
If you already run Uptime Kuma, it covers basic expiry alerts for your HTTPS sites. CertAvert adds the checks it doesn't do, and keeps working when your own server is the one that is down.
Sources: github.com/louislam/uptime-kuma, github.com/louislam/uptime-kuma/releases, github.com/louislam/uptime-kuma/wiki/Notification-Methods
We check each product's own pages and do our best to keep this right, but mistakes are possible and products change. Something wrong or out of date? Write to support@certavert.com.