Resolve Different Results

I am working towards trying to decide which tool is the best to use to measure site speed for my site. Using WebPageTest my results are consistently much greater than results for the same page (same timeish) using GTMetrix and much greater than results recorded in Google Analytics.

Average Results for a specific Page
WebPageTest: 22s
GTMetrix 7.6s
Google Analytics (daily average not a time point only) 8s

Has anyone run into this problem before?

Why is WebPageTest reporting a much greater page load time than GTMetrix or GA?

Any thoughts or suggestions are greatly appreciated!

In Google Analytics, try reducing the data set to look at a specific page and first-time visitors (advanced segments). That will get you a similar visit to what GT Metrix and WPT measure. Then go look at the histograms rather than averages to see where most of your users fall.

The default WebPagetest connectivity profile is a relatively slow DSL connection. If your users tend to visit mostly from work or skew higher then you’ll get more representative results by switching to Cable or different faster connection (the connection type is selectable in the advanced settings).