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Uptime Cairn

Free plan APILinuxSelf-hostedWeb

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Uptime Cairn's own site

What Uptime Cairn is

Uptime Cairn is a free, open-source monitor for websites and servers that runs on your own infrastructure. It checks HTTP and HTTPS, TCP, ICMP, DNS, TLS and domain expiry, push heartbeats, Docker containers, and gRPC services. Failed checks can open incidents with an acknowledgement and update timeline, and alerts can go to channels including email, webhooks, Slack, Discord, Telegram, Microsoft Teams, and SMS through Twilio. Public status pages support custom domains and branding, with 7 to 365 days of uptime history and email or webhook subscriptions using double opt-in. Scheduled branded reports can be produced as PDF, HTML, CSV, or JSON, and the REST API can script actions available in the interface. The software runs in one Docker container and uses one data file, with no separate database server. The site describes capacity of 5,000 monitors on one installation and 250 checks per second at a 20-second interval. It recommends a reverse proxy before internet exposure. There is no hosted tier; multi-region probing, SSO, and synthetic browser flows have not shipped.

Who it suits

It suits people who self-host, want monitoring data on their own infrastructure, or need an API and branded status pages. It is not a hosted service.

What it does well

  • Supports a wide range of network and service checks.
  • Status pages allow custom domains and branding.
  • Provides a REST API and scheduled reports.
  • No features are held back for a paid tier.

What to know first

  • There is no hosted tier.
  • Multi-region probing, SSO, and synthetic browser flows have not shipped.
  • The site recommends a reverse proxy before internet exposure.

Limits

The free plan is self-hosted, with no per-monitor pricing and no features held back for a paid tier. Multi-region probing, SSO, and synthetic browser flows have not shipped; the site describes a scale of 5,000 monitors per install and 250 checks per second at a 20-second interval.

Plans

PlanBilled and limitsPrice
FreeFree, open source, self-hosted; no per-monitor pricingFree

As uptimecairn.dev lists them, read 9 Oct 2026. The maker's own page has the final word.

Getting started

  1. Visit the Uptime Cairn website.
  2. Run it on your infrastructure as a Docker container.
  3. Configure checks and alert channels.
  4. Publish a status page or use the REST API as needed.
  5. Put a reverse proxy in front before exposing it to the internet.

Verdict

Uptime Cairn offers broad monitoring, alerting, reporting, and status-page features in a self-hosted package. Its lack of a hosted tier and the listed unshipped features matter if you need those capabilities.

Questions

How much does Uptime Cairn cost?

The Free plan costs nothing. It is open source and self-hosted, with no per-monitor pricing.

Is there a hosted version or free trial?

The site says there is no hosted tier, and there is no free trial.

Which platforms does it support?

The listed platforms are API, Linux, self-hosted, and web.

What license does Uptime Cairn use?

It is released under the Apache 2.0 license.

Can it publish status pages and send reports?

Yes. Status pages support custom domains and branding, and scheduled branded reports can be generated in PDF, HTML, CSV, or JSON.

Does Uptime Cairn have an API?

Yes. Its REST API can script actions available in the interface.

Facts from Uptime Cairn's own pages

Alerts
Alert channels include email, webhooks, Slack, Discord, Telegram, Matrix, Gotify, ntfy, Pushover, Microsoft Teams, Mattermost, Google Chat, PagerDuty, Opsgenie, Twilio/SMS, and Apprise. · uptimecairn.dev, 9 Oct 2026
API
The product provides a REST API that can script the actions available in the interface. · uptimecairn.dev, 9 Oct 2026
Checks
It checks HTTP and HTTPS, TCP, ICMP, DNS, TLS and domain expiry, push heartbeats, Docker containers, and gRPC services. · uptimecairn.dev, 9 Oct 2026
Deployment
It is self-hosted and runs as one Docker container with one data file and no separate database server. · uptimecairn.dev, 9 Oct 2026
Incidents
Incidents can open from failing checks and include an update timeline and acknowledgement. · uptimecairn.dev, 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. · uptimecairn.dev, 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. · uptimecairn.dev, 9 Oct 2026
Limitations
The site says there is no hosted tier, and multi-region probing, SSO, and synthetic browser flows have not shipped. · uptimecairn.dev, 9 Oct 2026
Purpose
Uptime Cairn monitors websites and servers and tells you when they go down. · uptimecairn.dev, 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. · uptimecairn.dev, 9 Oct 2026
Scale
The product site describes 5,000 monitors on one install and 250 checks per second at a 20-second interval. · uptimecairn.dev, 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. · uptimecairn.dev, 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. · uptimecairn.dev, 9 Oct 2026

Where Uptime Cairn stands on Freedom251

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