How to Turbo-Charge Firefox 3.1 Beta

Firefox 3.1’s first beta is upon us, right on track with the latest timeline for its release. The most anticipated new feature, though, isn’t there yet — at least, not unless you know how to make it show up.

Mozilla has disabled the much-touted TraceMonkey JavaScript engine — you know, the one said to rival Chrome’s V8 engine when it comes to speed. Engineers promise it brings a 40 times faster rendering speed compared to Firefox 3.0. Here’s the secret, though: It’s built into the first beta. It’s just turned off by default.

To give it a test run, type about:config into the address bar. Then type javascript.options.jit.content into the “Filter” field that pops up, and double-click it to set it to “True.” Restart the program and your speed booster will be on. (Mozilla hasn’t mentioned why it left the engine hidden as of now, so use at your own risk — it may or may not be fully stable yet.)

Here are the other improvements listed as being built in to 3.1 Beta:

  • Web standards improvements in the Gecko layout engine
  • Added support for CSS 2.1 and CSS 3 properties
  • A new tab-switching shortcut that shows previews of the tab you’re switching to
  • Improved control over the Smart Location Bar using special characters to restrict your search
  • Support for new web technologies such as the

Remember, other options — things such as the Chrome, IE8, and Safari-esque “private browsing” mode, or the Chrome-inspired tab-dragging capability — aren’t set to hit until Beta 2. That second beta is scheduled to be locked down on November 4 with a release a couple of weeks thereafter. The final 3.1 release is expected to come either late this year or early in 2009.