Open Source Checkly Alternatives

Uptime Kuma is a self-hosted monitoring tool with a reactive interface and a short path from install to first check. It watches the endpoints you care about and notifies you when one stops answering, without sending your monitoring data to a third party.

Checks can run as often as every 20 seconds, and the whole thing serves on a single port. It is a Node application, so it runs either as a container with a mounted volume or as a plain process kept alive by pm2.

What you can watch, and how you hear about it, covers most of a small fleet.

• Monitor types: web endpoints with keyword or JSON query checks, TCP, ping, DNS records, websockets, push, Docker containers and Steam game servers.
• Notifications: Telegram, Discord, Slack, Gotify, Pushover, email over SMTP, and more than ninety other services.
• Status pages: several of them, each mappable to its own domain.
• Certificates and proxies: certificate details and proxy support alongside a ping chart.
• Accounts: two-factor authentication, plus translations into many languages.

Docker Compose is the quickest install, though the container must not be backed by NFS storage. A non-Docker setup needs Node 20.4 or newer, Git and pm2, and runs on the major Linux distributions or on Windows 10 and Windows Server 2012 R2 upward. The BSDs, Replit and Heroku are not supported.

Gatus is a health dashboard aimed at developers, and its README opens with the objection you would raise anyway. Why not use Alertmanager, CloudWatch or Splunk. The answer is that those rely on existing traffic, so if nobody is calling a broken endpoint, nothing fires and your clients find the outage before you do.

Gatus calls the endpoints itself on a schedule using HTTP, ICMP, TCP or DNS queries, then evaluates the result against conditions you write. A condition can test the status code, the response time, the body, the certificate expiration or the resolved IP address, which makes the same mechanism usable for automated user acceptance tests.

The design choices show up in daily use.

• Readable configuration: adding an endpoint to monitor is a short block of YAML, not a project.
• Alerting breadth: Slack, Teams, PagerDuty, Discord, Twilio, Telegram, Opsgenie and dozens more, plus custom providers.
• Low resource use: a Go binary small enough to sit in a cluster without anyone noticing it.
• Badges: uptime and response time badges served from the API for embedding elsewhere.
• Security options: basic authentication, OIDC, TLS encryption and exported metrics are all configurable.

Storage, maintenance windows, announcements, client behavior, tunneling and custom labels are configurable too, alongside experimental support for remote instances and an alpha suites feature for grouping related checks.

A single docker run command starts it on port 8080, which is enough to have real endpoints monitored within a minute. Its author runs it in a Kubernetes cluster watching his own core applications.

OpenStatus puts status pages and uptime monitoring in the same tool, so the checks that detect an outage and the page that tells your users about it share one system. There is nothing to wire between a monitoring service and a separate status host.

Checks run from 28 regions in parallel across three cloud providers. The dashboard is a Next.js application, the API server runs on Hono, the checker is written in Go, and data lands in Turso through Drizzle with Tinybird handling analytics.

Everything the dashboard does is also reachable outside it.

• Status pages: custom domains, password protection, maintenance windows and subscriber notification by email and RSS.
• Monitoring: servers, websites and APIs watched from every region, with alerts through Slack, Discord, PagerDuty and email.
• Monitoring as code: YAML configuration driven from the CLI, GitHub Actions or Terraform.
• API: typed JSON over HTTP with a Node SDK, sharing a single key with the CLI.
• MCP server: connects an assistant such as Claude, ChatGPT or Cursor to your workspace.

Docker Compose is the fastest way to run it, and pre-built images cover the server, dashboard, status pages, workflows, checker and private locations, the last of these fitting in an 8.5MB image. Guides exist for one click deployment to Coolify and Railway, and the managed service charges a flat price with unlimited members.