Upptime

Upptime is a free, open-source, self-hosted uptime monitor and status page powered entirely by GitHub Actions and GitHub Pages. Created by Upptime contributors and maintained by the community, Upptime has over 16,000 stars as of 2026, making it one of the most popular monitoring solutions in the open-source world. Unlike traditional monitoring services like Pingdom, UptimeRobot, or StatusPage.io that charge monthly fees and require server infrastructure, Upptime runs entirely within GitHub's free tier, requiring zero external servers, zero monthly costs, and zero ongoing maintenance. Key features include: GitHub Actions-based monitoring (scheduled workflow runs that periodically check your sites every 5 minutes via HTTP HEAD/GET requests, measuring response time and status codes), response time monitoring (tracking and graphing response time trends over the past day, week, month, and year using interactive charts), uptime percentage calculation (displaying 24-hour, 7-day, and all-time uptime percentages per monitored site), incident history (recording every downtime event with start time, end time, duration, and severity), commit-based configuration (editing a single YAML file in your repository to add, remove, or modify monitored sites, with all configuration version-controlled via Git), automatic status page generation (a beautiful, responsive status page deployed to GitHub Pages with zero configuration, showing real-time status, response time graphs, and incident history), notification system (sending alerts via Slack, Discord, Telegram, webhooks, email, and SMS when sites go down or recover), custom domains (using a custom domain for your status page via GitHub Pages CNAME), site categorization (grouping monitored sites into categories for organized display), multi-region monitoring (configuring different GitHub Actions runners in different geographic regions), and SSL certificate monitoring.