Monitority!

Monitors your websites every 5 minutes, totally free. Get alerts by e-mail, SMS, Twitter or RSS. Add up to 50 websites. Monitors can be refreshed for an instant check with a click. Supports https and authentication with user/password.

Pingdom web site monitoring and other infrastructure for you and instantly let you know when anything goes wrong. Measure uptime, downtime, and the performance of your website as experienced by visitors.

Cabot is a free, open-source, self-hosted infrastructure monitoring platform that provides some of the best features of PagerDuty, Server Density, Pingdom and Nagios without their cost and complexity.

Port Monitor is an easy and online tool that does website and server monitoring for you 24/7 every 60 seconds and sends you or your co-workers instant email/push notifications when something goes wrong.

The AppBeat Android app lets you connect to your AppBeat uptime monitoring service from anywhere, anytime. You can view current live status of your checks and do basic check management:• Create simple web checks• pause/resume specific check or entire group of checks

RapidSpike is an uptime and performance monitoring service for websites and web applications. It simplifies monitoring, alerting and reporting to support your online presence and to ensure a positive user experience. Organisations use it to identify problems, measure performance and improve capacity planning.

Free Website Monitoring. Be notified when your site is down.

With webcron you pay per request and you can choose the monitoring frequency to your linking. When your website goes down, webcron can send you either an email or a text message (SMS).

Free & Simple website monitoring

isUp.li | Website Monitoring

HetrixTools' Blacklist Monitor is the quick and simple way to monitor your IPs/Domains and notice if any of them get blacklisted on over 180 blacklists, so you can immediately take action to find the cause and start the delisting procedures, before it gets to affect your clients or your reputation.

UptimePal offers an affordable website monitoring service. For only $1/month per URL, you get 1-minute uptime monitoring, alerting software, & performance test tools - all from a robust worldwide monitoring network.

by owner:"Monitors your website/server for free, 30 seconds interval. Complete delivery test for e-mail servers (sends an e-mail, waits for it to arrive). Alerts via SMS/e-mail. Worldwide network.

Pingoscope will carefully monitor your website and alert you instantly if it goes down. Unlimited email SMS, Skype, Phone Call notifications, historical response time data, one minute check intervals data and more features available for free as well as no limit accounts for affordable price.

Netthrob’s servers take their job very seriously. They buzz vigorously from five strategic locations across the world and track the uptime of your website. The coordinated monitoring action from different geo locations gives a very accurate status of your website’s uptime and downtime. Netthrob can precisely point out geography-specific visitor experiences so that you can alter your Content Delivery Network (CDN) resourcing accordingly.