The new features of WebPageTest were demo'ed at Velocity 2010 Lightning Demos session.
One distinct feature in PageTest is Visual Performance comparision. A Waterfall chart is what most web performance analysis tools show. With PageTest you can see how your web page actually looked like at small intervals while it was still loading. You can choose between a Film-strip view & Full-motion video to know what your site visitors see when they access a web page on your website.
WebPageTest now offers more test locations, custom bandwidth configuration, browser resource utilization info (CPU & Network bandwidth) and support for HAR (HTTP Archive Specification)
HAR is an open format for archiving & exchange performance results between web performance analysis tools. The current list of tools that support HAR is here.
Related:
HOW TO measure page load times across continents for free
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