Both of these tools are GREAT for analyzing a website. So which one should you guys be using?
I would recommend tools.pingdom.com because its faster and easier to read.
GTmetrix is really more for developers and it dives much deeper into whats going on with a website. With pingdom you just want to look at 2 things.
- Performance Grade (Should be above 90)
- Load time (should be below 4 seconds, ideally under 2.5 seconds)
Just like anything else though, you may not get the same results as your client. Many times a client will not notice a lag on their site. This is because they have gone to their site regularly and they are actually viewing a cached copy of their site so it loads VERY fast. In these cases I would send the client to pingdom to test the site themself, or just send them the URL of the test you ran.