1. NodePing Server Monitoring and Web Site Monitoring. Simple but powerful Internet service monitoring.

  2. Radar Website Monitor is a multithreaded website monitoring tool, watching different protocols, including HTTP, SMTP, POP3, FTP, TCP, DNS and Database.

  3. PHP Server Monitor is a script that checks whether your websites and servers are up and running.

  4. I found a great domain name for sale. Check it out!

  5. Avospy offers website monitoring, instant alerts, SEO analyzer, spying competition to get precise statistics about error on the website.

  6. Detect is a chrome extension that allows you to track any change on a website.

  7. Self-hosted, easily-deployable monitoring and alerts service - like a lightweight PagerDuty

  8. Testomato checks both public and password-protected areas of your website with automated tests for error messages, HTTP status codes, missing content, broken forms, missing Google Analytics code and blank pages.

  9. Receive instant alert notification when your website goes down. Easy to use user interface.

  10. 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.

  11. NetCrunch IT Monitoring Platform is easy to start and enterprise scalable. It allows monitoring of systems, logs, applications, cloud and SNMP devices.

  12. Free website monitoring service checks your site from worldwide locations and alerts you instantly via email or SMS when it becomes unavailable. Detailed uptime statistics and performance reports available.