GTmetrix adds Test Server Regions and HAR Diff

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Adrian Yee

Jun 15, 2011, 1:05:43 PM6/15/11

We're pleased to announce two major features that we recently pushed live onto

* Test Server Regions
* HAR Diff - visual diff for HAR files

Test Server Regions

In addition to our main test server in Vancouver, Canada, you can now test your
URL in Dallas, USA, London, UK, and Sydney, Australia. Like the other test
options, log in to access this new functionality.

Compare URLs in different regions to see the difference in geo-targeted content,
CDN performance and load times. Page Speed and YSlow scores shouldn't change
too much, but your page load times and waterfall graphs should.

HAR Diff

We've always wanted a way to easily compare the differences between two HAR
files and now it's possible with HAR Diff! We've made an add-on to Jan
Odvarko's HAR Viewer ( that
allows you to compare two waterfall graphs side-by-side.

You can see it in action here (be sure to view the larger version of it):

This visual comparison can help highlight differences between two waterfalls
such as:

* The impact of latency on your pages and its resources from different locations
* Geo-targeted content
* Optimizations performed (eg. minified and combined files)
* Differences in browser loading

We have submitted some patches to the HAR Viewer project (which have already
been accepted) and we're getting the rest of the HAR Diff code ready for release
(it will be an open source add-on) so you can also add HAR Diffs to your project

We would love to hear feedback from the community on HAR Diff so that we can
make it even better.

You can read more about HAR Diff here:


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