System Monitoring & Alerting Tools
4 open source monitoring and alerting tools you can self-host. Compare Nagios, Zabbix, and New Relic alternatives by metrics, uptime, and license. Updated Sept 2026.
Healthchecks
Healthchecks is an open-source cron job and background task monitoring service, and a self-hosted alternative to Cronitor and Dead Man's Snitch. Scheduled jobs check in with an HTTP ping after each run; if a check-in doesn't arrive on schedule, Healthchecks alerts the team by email, Slack, SMS, or 25+ other integrations.
OpenStatus
An open-source synthetic monitoring platform that helps monitor websites and APIs globally, providing notifications about downtime and performance issues.
Checkmate
An open-source uptime and infrastructure monitoring application that tracks the operational status and performance of servers and websites, providing real-time alerts and comprehensive monitoring capabilities.
Gatus
A proactive endpoint monitoring tool that performs health checks on services, providing real-time alerts and performance insights for modern applications.
Uptime Kuma
A self-hosted monitoring tool for tracking website and service uptime with an easy-to-use interface and extensive notification capabilities.