Mozilla cracks down on slow starting Firefox add-ons

By on April 4, 2011, 8:00 AM
Firefox's expandability through add-ons is often cited as a key feature of the browser, but it is also known to be a source of sluggish performance and slow startup times, particularly when running several add-ons simultaneously. Things have notably improved with the release of Firefox 4, but there's still work to be done, and as such Mozilla is starting an initiative to get add-on makers to optimize their programs.

According to Mozilla's Justin Scott, Product Manager for Add-Ons, the average Firefox extension increases startup time by about 10%. The actual impact in seconds will depend on the hardware and software a user is running, but the company estimates that installing 10 add-ons will double the amount of time it takes the browser to launch.


To that end the company will begin running automated performance tests on the top 100 add-ons and post the results here on a weekly basis. The worst offenders currently include the FoxLingo Translator/Dictionary and Firebug website debugging tool, both of which slow down the browser's load time by 74%. The popular Xmarks ranks ninth with a 30% slowdown, and FastestFox, which promises to make browsing faster, will slow down Firefox 33% when launching.

Mozilla is contacting the developers of the worst performing add-ons to encourage them to improve their performance and will provide a performance-measuring tool for them to test against. The company says that developers should be aiming for a "5% start-up impact or less."

Within the next two weeks, Mozilla will add a warning to any add-on that slows Firefox's startup time by more than 25%, and in an upcoming version of the browser, third-party add-ons from standalone software vendors will not be installed unless the user specifically approves the installation (think browser toolbars and the like). This should have a significant impact on Firefox performance and give users back the control they should have over their add-ons, according to Scott.

Add New Comment

TechSpot Members
Login or sign up for free,
it takes about 30 seconds.
You may also...
Get complete access to the TechSpot community. Join thousands of technology enthusiasts that contribute and share knowledge in our forum. Get a private inbox, upload your own photo gallery and more.