Monday, December 04, 2006

Performance Tip of the Day: Script Tags are Blocking

Today I downloaded the fantastic firebug extension. It has a mode where it shows network activity:

I learned that if you have a JavaScript file, the browser will block rendering of the page until the request is done. I saved about 100ms on a few sites I run by moving the Google Analytics tracker to the bottom of the page (not sure why it wasn't being cached, probably because I am on an SSL site).