Do you ever wonder what's going on inside the browser when a webpage doesn't load or respond as quickly as it should? Many developers do, especially when trying to build powerful web applications for their users.

But up until now, it's been difficult for developers to identify problems in a slow-to-respond application. So, tonight at Google Campfire One, we're happy to announce that we're adding a new tool to Google Web Toolkit called Speed Tracer.

Speed Tracer is a Google Chrome extension that enables developers to identify performance problems in their web apps using a "Sluggishness Graph," in combination with many other metrics. In the spirit of clean, simple design, developers need only look at the Y-Axis of their application's Sluggishness Graph to see how they're doing:

• If the y-axis is close to zero, then the app is fast
• If the y-axis registers around 100%, then the app is, well, sluggish

And in either case, Speed Tracer provides lots of additional data to help diagnose any particular performance issue.

We think developers will find that Speed Tracer looks under the covers of web applications like never before. In fact, we even used Speed Tracer to optimize the performance of Speed Tracer itself! (It's really an HTML5 application after all, built with Google Web Toolkit, and deployed as a Google Chrome extension.) If you're a web developer, download and install Speed Tracer on the Google Chrome Developer Channel.



This is one of many other improvements in GWT 2.0 — which we released at this evening's Campfire — that make building web applications fast, and the applications you build run even faster. Check out the Google Code Blog for more information and to watch our Campfire One developer announcement.

Posted by Bruce Johnson, Engineering Director