CheckCle is a self-hosted, open-source monitoring platform that gives developers, sysadmins, and DevOps teams real-time uptime, infrastructure, incident, and alert visibility across full-stack systems, applications, and services, and it can be deployed anywhere.

What it is

CheckCle is an MIT-licensed monitoring platform written in Go, sitting in the Infrastructure & Operations / Monitoring & Observability category. It combines uptime checks for HTTP, DNS, Ping, and TCP-based services (FTP, SMTP, HTTP), infrastructure server monitoring for Linux and Windows (Beta), SSL and domain expiry tracking, incident history, scheduled maintenance, public status pages, and multi-channel notifications in one self-hosted application. It runs on Docker (the topic list includes docker and container) with PocketBase as its backend, and it ships as the image operacle/checkcle:latest.

The problem it solves is tool sprawl. The project consolidates the separate point tools teams otherwise assemble for uptime checks, server CPU, RAM, disk, and network metrics, SSL certificate expiry tracking, incident timelines, and public status pages, and it wires them to a single alerting layer. Instead of running one service for reachability, another for host metrics, and a spreadsheet for certificate renewals, a self-hoster runs one container and gets these views under one settings panel with user management, data retention, and alert templates.

Key capabilities

• Uptime checks over HTTP, DNS, and Ping protocols, plus TCP-based and API services such as FTP, SMTP, and HTTP.
• Distributed Regional Monitoring, running checks from multiple regions and tracking response times and performance.
• SSL & Domain Monitoring that records domain, issuer, expiration date, days left, status, and last notified.
• Infrastructure server monitoring for Linux (Debian, Ubuntu, CentOS, Red Hat) and Windows (Beta), reporting CPU, RAM, disk, and network activity through a one-line installation agent script.
• Incident History with UP, DOWN, WARNING, and PAUSE states, alongside scheduled maintenance and incident management.
• Notifications through email, Telegram, Discord, Slack, Matrix, and more, configured as channels and alert templates.
• Operational status and public status pages, with reports and analytics.

Who uses it and how

• Developers, sysadmins, and DevOps teams that need insight across servers, applications, and services.
• Self-hosters running Docker Compose on x86_64 PCs, laptops, and servers (amd64), Raspberry Pi 3/4/5 with a 64-bit OS, or Apple Silicon Macs (arm64).
• Teams needing public-facing operational status pages and routed alerts across email, Telegram, Discord, Slack, and Matrix.
• Operators with geographically spread services that require distributed regional checks.
• Evaluators, who can try the live demo at demo.checkcle.io before deploying.

Getting started

The recommended path is Docker Compose with the image operacle/checkcle:latest, mapping port 8090 and the host directory /opt/pb_data to /mnt/pb_data; a single docker run command is provided as an alternative. The admin interface is served at http://0.0.0.0:8090 with the default credentials [email protected] / Admin123456, and the Quick Start Guide lives at docs.checkcle.io.

How it compares

No comparable tools are named anywhere in the facts for this listing, so CheckCle stands alone in this registry. Its distinguishing facts are the MIT licence, the self-hosted Docker deployment, and the absence of a paid tier — the README states it is completely free to use with no hidden costs, and sponsorships are no longer accepted.

When to use it — and when not to

A self-hoster must operate a Docker host, keep the /opt/pb_data volume persistent, manage the PocketBase backend, expose port 8090, raise the file-descriptor ulimits (nofile 4096 soft, 8192 hard), and configure notification providers such as email, Telegram, Discord, Slack, and Matrix. Teams that want a fully managed service with no operational load should not pick it, and Windows server monitoring is still marked Beta, so parity with Linux is not guaranteed. The repository also carries 92 open issues, worth weighing before adopting it for critical infrastructure.