Whether site downtime means loss of revenue or just loss of face, or you need to stay a step ahead of your clients, these services offer you a completely free way of knowing what's up, what's down and in some cases, why.
Read on for our list of ten suggested solutions, but as this list is by no means exhaustive, please do share any services you favor in the comments.
1. UptimeRobot
Number of Sites you can Monitor: 50
Regularity of Checks: Every 5 minutes
Methods of Alerts: E-mail, SMS, RSS, Twitter coming soon
UptimeRobot looks at your site header's status codes every five minutes and if the code comes back with a problem, does further checks. Then, if there are still issues, it lets you know about it pronto. Created by two devs who think the web should be free or cheap, it's guaranteed a no-payment service until August 2010, so hop over now to check it out.
2. Pingdom
Number of Sites you can Monitor: 1
Regularity of Checks: User set, from 1 minute upwards
Methods of Alerts: E-mail, SMS (up to 20 per month), push alerts via iPhone app
Pingdom is a big boy of the paid monitoring services market, but does offer a very basic free account. Although the free service only lets you monitor one site, we feel it's particularly worthy of mention since it comes with a free iPhone app gives you a handy on-the-go solution for monitoring your website's status.
3. Mon.itor.us
Number of Sites you can Monitor: 1
Regularity of Checks: Every 30 minutes
Methods of Alerts: IM, SMS, E-mail, RSS
Mon.itor.us is the free little sister service to Monitis and offers a simple set-up for its external monitoring. As well as alerts, the app tracks failures and logs a report of the uptime/downtime of your website per day, week or month and makes the reports available to you in real time.
4. InternetSeer
Number of Sites you can Monitor: 1
Regularity of Checks: Every hour
Methods of Alerts: E-mail, SMS, pager (!)
If sizes matters to you then you'll be interested to note that InternetSeer claims to be the largest website monitoring service, currently working for over 1.7 million sites worldwide. While it's been on the receiving end of some criticism for excessive email marketing, in addition to the ability to set up alerts to go to multiple contacts, the service generates a free weekly report.
5. Uptrends
Number of Sites you can Monitor: 1
Regularity of Checks: Every 30 minutes
Methods of Alerts: On-site info only
The free option from Uptrends is more suited to those who want to make uptime info readily available to their users, rather than an alert-based, service. Once you embed the button on your site, Uptrends monitors the uptime of your website every 30 minutes from worldwide checkpoints. Clicking the button will generate an uptime report of the last 24 hours, last 7 days, month and year.
6. BasicState
Number of Sites you can Monitor: Unlimited
Regularity of Checks: Every 15 minutes
Methods of Alerts: E-mail, SMS
BasicState will check the status of unlimited websites for you every 15 minutes and alert you either via e-mail or SMS if there's trouble afoot. There's also the option to generate a daily uptime report with a 2-week history and the service can be tailored to add default, backup and emergency alert schedules to your preferences.
7. Montastic
Number of Sites you can Monitor: 3
Regularity of Checks: Every 30 minutes
Methods of Alerts: E-mail, status via RSS and widgets for Macs and PCs
Montastic offers itself under the fabulous tagline of "the free website monitoring service that doesn't suck." The open source service checks from multiple locations in the U.S., so it might be best for sites that have an American audience. Tiered, paid-for options increase the amount of URLs you can get checked and reduce the time between checks.
Number of Sites you can Monitor: 5
Regularity of Checks: 25 times a day
Methods of Alerts:
The freebie option from Are My Sites Up? checks as many as five of your sites at least 25 times per day with unlimited email and SMS notifications that, in most cases, will help tell you why your site has gone offline by providing the HTML status error code. Paying up for the premium service opens up access to an iPhone app that is sadly not available for free accounts.
9. Site24x7
Number of Sites you can Monitor: 1
Regularity of Checks: Once an hour
Methods of Alerts: E-mail
The free service from Site24x7.com is basic, and offers monitoring of one URL every hour with e-mail alerts sent out in case disaster strikes. It's just one of several free webmaster tools from the company that also includes an anytime website uptime check, web page load time analysis and various DNS/IP search tools.
10. 100Pulse
Number of Sites you can Monitor: 2
Regularity of Checks: Every 15 minutes
Methods of Alerts: E-mail, RSS and a Google gadget
Along with e-mail and an RSS feed, 100Pulse's free website monitoring service will keep you updated on the status of two sites via a Google Gadget that you can add to your iGoogle homepage for an at-a-glance look at the status of your websites. As with almost all of the above, paying out gets you extra features, but the free service will cover you for the basics.
Series supported by Rackspace
Rackspace is the better way to do hosting. No more worrying about web hosting uptime. No more spending your time, energy and resources trying to stay on top of things like patching, updating, monitoring, backing up data and the like. Learn why.