UptimeRobot - Free Website Uptime Monitoring
Dynatrace - Cloud-based quality testing, performance monitoring and analytics for mobile apps and websites. Get started with Keynote today!
Pingdom - With website monitoring from Pingdom you will be the first to know when your website is down. No installation required. 30-day free trial.
ThousandEyes - ThousandEyes is a Network Intelligence platform that delivers visibility into every network your organization relies on.
Uptime Kuma - A fancy self-hosted monitoring tool.
LogicMonitor - LogicMonitor is the SaaS performance monitoring platform for the world's best IT teams. Deploy Fast, Monitor More, Improve Ops.