Uptime Cairn

What it does

Alerts

Alert channels include email, webhooks, Slack, Discord, Telegram, Matrix, Gotify, ntfy, Pushover, Microsoft Teams, Mattermost, Google Chat, PagerDuty, Opsgenie, Twilio/SMS, and Apprise.checked 9 Oct 2026

API

The product provides a REST API that can script the actions available in the interface.checked 9 Oct 2026

Checks

It checks HTTP and HTTPS, TCP, ICMP, DNS, TLS and domain expiry, push heartbeats, Docker containers, and gRPC services.checked 9 Oct 2026

Deployment

It is self-hosted and runs as one Docker container with one data file and no separate database server.checked 9 Oct 2026

Incidents

Incidents can open from failing checks and include an update timeline and acknowledgement.checked 9 Oct 2026

Intended users

The site describes it as a fit for people who self-host, want data on their own infrastructure, or need a write API and branded status pages.checked 9 Oct 2026

License

Uptime Cairn is released under Apache 2.0, and the site says no feature is held back for a paid tier.checked 9 Oct 2026

Limitations

The site says there is no hosted tier, and multi-region probing, SSO, and synthetic browser flows have not shipped.checked 9 Oct 2026

Purpose

Uptime Cairn monitors websites and servers and tells you when they go down.checked 9 Oct 2026

Reports

Scheduled branded reports can be generated as PDF, HTML, CSV, and JSON and delivered by email, Slack, webhook, or an S3 drop.checked 9 Oct 2026

Scale

The product site describes 5,000 monitors on one install and 250 checks per second at a 20-second interval.checked 9 Oct 2026

Security

The site says the Docker Compose reference includes a read-only root filesystem, no-new-privileges, and a healthcheck; it also says the default port binds to 127.0.0.1 and recommends a reverse proxy before internet exposure.checked 9 Oct 2026

Status pages

Public status pages support custom domains and branding, uptime history from 7 to 365 days, and email or webhook subscribers with double opt-in.checked 9 Oct 2026