Uptime Robot is a free tool used to monitor websites. It monitors your websites every 5 minutes and alerts you if your sites are down. Get alerted via e-mail, SMS, Twitter, push, Slack, HipChat and now OnPage through WebHooks. A reliable monitoring service is a must today. Set an HTTP/S, ping, port, keyword, or heartbeat monitor and get notifications to your email, phone, Telegram, Slack, Twitter, Zapier, and others.