Mozilla to boost Firefox add-on performance

Mozilla has improved the way Firefox handles add-ons in an attempt to reduce start-up times.

The firm said that the plethora of add-ons available for Firefox, many of which are from third parties, is having an adverse effect on performance.

"[Customisation is] extremely important and, while most add-ons cause only a tiny performance impact, others can significantly slow down Firefox. Many users don't realise add-ons can cause these delays, and that's why we're committed to improving performance in a big way," wrote Mozilla in a blog post.

"On average, each add-on you install adds about 10 per cent to Firefox start-up time. For some users that's mere milliseconds, and for others it may be half a second; it all depends on the hardware and software of each individual."

Based on the firm's research, and real world performance data, installing 10 add-ons can just about double the start time of the browser, a delay that Mozilla is hoping to tackle through a number of initiatives.

These include automated performance tests in which Mozilla will run weekly assessments on the way the top 100 add-ons affect start-up times.

The firm said that it will eventually report on software as soon as it is submitted, and will add information such as its impact on page load times.

Badly performing add-ons that slow down start time by over 25 per cent will come with a slow performance warning, which will also display in the users' Add-ons management settings.

Mozilla is offering some performance best practice guidelines for developers, and said it will reach out to those that are building slow add-ons.

Tools will also be released that should help developers design better performing applications, as will automated testing software.