Pathway to a faster Gmail

Performance improvements often go unnoticed, and that's okay. Great performance has always been an obsession at Google and it's something that Google thinks about and works on everyday. Every user wants Gmail to be really fast, and Google keeps working on ways to make it faster. Gmail's architecture eliminates many of the delays in reading mail by employing techniques like prefetching, but recently Google decided to take a close look at some other key parts of Gmail to see if they can speed things up.

One of the areas Google worked on was the initial loading sequence: everything that happens behind the scenes between the time you press the "Sign in" button on the login page and the moment you land in your inbox. While the improvements made won't resolve every "This is taking longer than usual..." message you might see when loading Gmail over a slow connection, I've seen a real reduction (up to 20%) in overall load time compared to when Gmail started.

Now there is a significant reduction in the number of overall HTTP requests, by making more of the requests cacheable by the browser, and reducing the overhead of each request. Also they reduced the weight of each request itself by eliminating or narrowing the scope of some of the cookies. Now all the images were cacheable by the browser, and now consolidated small icon images into single meta-images, a technique known as spriting. Even combined several requests into a single combined request and response.

The result is that it now takes as few as four requests from the click of the "Sign in" button to the display of your inbox.