R – How to test the performance of your website from multiple locations world-wide


Following on from How do you test the performance of a website? :

What tools/sites/services do you use to find out the performance of your website from multiple locations around the world?

There are always complaints that sites are slow under certain circumstances (especially from physically-distant places), and it would be nice to be able to tell where it is particularly slow from.

Best Solution

Pingdom are good, and quite cheap. They'll tell you if your site has suddenly started getting worse from one part of the world.

Gomez are excellent (they can test loading of all the images/css/js etc as well as the HTML itself, using the same pipelining rules as browsers use), and they can test not just from datacenter locations but end-user broadband connections - but they're very expensive.

It's also worth using a tool like YSlow to do basic analysis of your app and point out the things that are likely to cause problems over slow network connections.