Status.io - Status.io is a platform for system status pages and status notifications. Companies rely on Status.io to track outages, schedule planned maintenances, broadcast status notifications, and much more; and their customers love the transparency.

Uptime Kuma - A fancy self-hosted monitoring tool.

StatusPage.io - StatusPage.io is the best way for web infrastructure, developer API, and SaaS companies to get set up with their very own status page in minutes. Integrate public metrics and allow your customers to subscribe to be updated automatically.

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.

Statping - Status Page for monitoring your websites and applications with beautiful graphs, analytics, and plugins. Run on any type of environment.

StatusCake - Website Uptime Monitoring & Alerts – Free Unlimited Downtime Monitoring