Online service which allows you to specify Internet resources, web sites, or keywords that you want monitored.

The 24-hour monitoring service that lets you know the moment your website goes offline.

Monitor web sites, multi-page web transactions, and audio/video content. Some free services available.

Online interface to trigger ping and traceroute tests from more than 200 locations all over the world.

Remote web site monitoring and failure notification from global network, supports http, https, ping, smtp, pop3, imap4, ftp and tcp-level checks.

Free website monitoring service based on retrieving a short text file. E-mail and/or pager notification. With an overall list of monitored sites and their status.

Server port monitoring, content checking, host process verification, and router latency/packet loss monitoring.

Monitors websites and other internet servers for availability and performance. Alerts users when their sites or servers are unavailable or performing poorly. Alerts via email, pager, or SMS. Free trial.

Global web site monitoring service providing web application monitoring, network monitoring, website load stress testing with reporting, notification, escalation and analysis in one single solution.

Provides web-based network monitoring solutions.