Forum Moderators: DixonJones
Free: [siteuptime.com ]
Paid: [alertra.com ]
They both seem to be quite good although if you only have a minute or two of downtime and they check your site at that particular time it can be a bit misleading.
Just following up on the notion that "if it looks to good to be true, it probably is" ;-)
First, the don't download a page, they just ping a specific port (e.g. http/80). This will tell you that there's a network problem, or that your web server has bitten the big one, but not much more granularity than that.
Second, I found out they don't check pages after checking back to the site and seeing that my service had been "failing" all day long because I had put in a full URL, not just the domain name. I never got paged.
I guess you get what you pay for.
And on that score, update on Keynote: their "$50/month" service comes with a $19.95 "account set up fee" (according to the quote) or "base device fee" (according to the sales person), for a total of $70/month. I wish he had just told me it was $70/month to start!
:-)