Top 10 Best Website's Uptime Monitoing service1. Pingdom
Pingdom is cool about website, server monitoring. Almost got 400000+ customers include Google, Twitter, Pinterest, Microsoft. Free account for website monitoring available. 1 minute interval instant inform via sms-email.
2. Site uptime
Site uptime is a website monitoring service that checks your website or server 5 minutes interval from several location. Free site monitoring available and it has 30 minutes frequency.
3. Dot Com monitoring
Service include website monitoring, web apps, business transaction, monitoring, network device monitoring, reporting, Analysis and graphs, Alerts, notification and escalation, site load speed stress test. Free trial available
Website, server monitoring, transaction and lots of features. Uptrends is a leading monitoring service provider having customer like Toyota, Sony, eBay. 14 days trial
5. Internet vista
"Uptime is money" They monitor all of internet service. 24 hours a day 7 days a week! If your site become unavailable or malfunction you will be immediately notified
6. Monitor Us
Free service offers 30 minutes interval, premium service has 5 minutes frequency server uptime check, visitor tracking so on. Supported any type of protocols.
7. Internet Seer
More than 2.5 million website monitored and 2.2 million monitoring. Free trial for premium service available 14 days. plus free web monitoring available.
8. Status Cake
Unlimited website monitor and reliable. No matter what big or small business website you run. They have customer like Disney, Ea games
9. Uptime Robot
Uptime Robot is more than meets the eye! One account 50 url check, 5 minutes interval, instant email-sms for free.
10. Service Uptime
Service uptime will make sure your site is available for 24x7x365. Multiple location supported ports are page, link, apps, webmail port, ftp. Free account don't have much feature.
So use one of these service you use and if you already didn't signed up don't forget to mention which one will use :)