How does this work?

Our site tries to load your site. When that happens we get an HTTP Status Code back. If that number is anywhere in the 200's or 300's, your site is cool. Otherwise, there is some kind of error resulting in your site being down for visitors, and that triggers our system for handling down sites (you get the email, the icon goes red, etc.)

What if THIS site goes down?

While obviously that isn't ideal, it's not as bad as you might think. The front-end and the back-end of the site are totally separate. If you aren't able to load the site, don't worry! Your sites are still being checked in the background and you will still be notified. Not once has the backend of our service gone down.

Stuff that isn't going to work.

If your site is behind password protection to see the site at all, like htaccess password protection for example, we are going to get a 401 Status Code and your site will appear down. HTTPS is supported on paid plans only.

How often does it check?

Premium Plus and Pro users will have their sites checked every 15 minutes or faster; Premium Standard, 30 minutes or faster.

You will get one notification when a site goes down (per notification method), and one when it comes back up.

Does it register a pageview on my site?

Not really. If you use analytics software that uses JavaScript (Like Google Analytics, Mint or Woopra) or an image on your page to do its tracking, it probably won't notice us at all. We are using a Ruby function that is similar to cURL to get our result. If you use server-side analytics software (that actually parses server logs), then you will see us hitting your site.

If you like to set up a filter, the IP's of our servers are 72.2.116.95, 72.2.117.212, and 174.143.240.5 - Your site could be checked by any of those and may change, so it's best to filter all of them.

Cool icons!

Thanks, they are from Function.

Who built this site?

Richard Felix Jr. (Twitter) is the lead developer. Chris Coyier (Twitter) designed it. The service itself is on Twitter as well.

What hosting do you recommend?

To be clear, it doesn't matter who hosts YOUR websites, we can perform checks on any host. But if you are looking for recommendations, we happy recommend Joyent hosting. We are hosting on Joyent as we speak, and have been since day one. They offer powerful, scalable and reliable hosting options.