Open-source Dead Man's Snitch alternatives

Uptime Kuma is a self-hosted tool that watches whether your services are up and tells you when they are not. You run it on your own server, point it at the endpoints you care about, and it records response times, certificate details and outages in a responsive web dashboard.

Supported monitor types include HTTP(S), TCP, keyword and JSON query checks, WebSocket, ping, DNS records, push-based heartbeats, Steam game servers and Docker containers, with checks as frequent as every 20 seconds. Alerts can go to Telegram, Discord, Gotify, Slack, Pushover, email over SMTP and more than 90 other notification services. You can publish several status pages and map them to your own domains.

It is MIT licensed and mainly distributed as a Docker image, with a Docker Compose setup and a non-Docker route that uses Node.js and pm2. Extras include proxy support, two-factor authentication, multiple UI languages and ping charts. Network file systems such as NFS are not supported for its data directory.

Healthchecks is a monitoring service for cron jobs and scheduled tasks. Each job sends a ping over HTTP or email when it runs, and Healthchecks raises an alert whenever an expected ping fails to show up in time. This catches silent failures of backups, imports and other background work that would otherwise go unnoticed.

Every check has a period, which is the expected time between pings, and a grace time, which says how long to wait before alerting, or it can follow a cron expression instead. The product includes a live web dashboard, an API, more than 25 notification integrations, monthly email reports, WebAuthn two-factor authentication and team features such as projects, members and read-only access. Status badges with hard-to-guess public URLs can be embedded in READMEs or status pages.

Healthchecks is written in Python with Django and uses PostgreSQL, MySQL or MariaDB. It is licensed under the BSD 3-Clause licence and can be self-hosted, with a Dockerfile and prebuilt Docker images provided, or used as the hosted service at healthchecks.io.

OneUptime is an open-source monitoring and observability platform that aims to replace a shelf of separate SaaS tools. It covers uptime monitoring, status pages, on-call and alerting, incident management, logs, traces, metrics, APM and error tracking in one application, and adds AI-assisted features such as helping find the root cause and proposing a fix.

Its README maps each module to the tools it can replace: Pingdom and UptimeRobot for uptime checks across websites, APIs, ports, SSL and DNS, StatusPage.io for branded public and private status pages, PagerDuty and Opsgenie for schedules, escalation policies and SMS, call, push or Slack alerts, Incident.io for declaring and triaging incidents with post-mortems, Datadog and New Relic for traces and dashboards, Loggly for logs, and Sentry for exceptions.

The Community Edition is open source under Apache 2.0 and free to self-host, and OneUptime Cloud offers a free-forever plan with no credit card. It is written in TypeScript. It suits small and mid-sized engineering teams that want one platform for reliability work rather than integrating many vendors.