Mozilla plans to reduce power consumption of Firefox

Martin Brinkmann
Sep 15, 2015
Updated • Sep 15, 2015

Power consumption has risen to importance in the browser world ever since mobile became the new battle ground. While it is not the only metric that matters and probably not something that most users pick a mobile browser by, it seems to gain some prominence lately due to mobile device power requirements and a lack of breakthroughs in battery technology.

A study from 2014 by Anandtech compared the battery life of a Dell XPS 15 laptop when running popular browsers and Firefox did not perform overly well in the test when compared to Internet Explorer specifically.

Firefox is not the only browser that could do better though. A recent test by the Verge showed that Chrome tapped out after less than 10 hours on a new MacBook Pro with Retina display while Safari did not until 13 hours had passed.

Another recent test concluded that Chrome is doing worst when it comes to battery usage followed by Firefox and then Internet Explorer.

There is also the Energia Dashboard highlighting cpu and power consumption of Firefox, Chrome and Internet Explorer on popular websites.

Mozilla's Project Candle aims to improve the power consumption of Firefox on all platforms it is offered on (meaning desktop, mobile and Firefox OS).

This is done mostly by evaluating power bugs that exist on Bugzilla but also by adding new bugs that introduce power-related improvements to Firefox to Bugzilla.

firefox power bugs consumption

The team is working its way through all power-related bugs currently to sort them by priority. It plans to address high priority bugs first, for instance those that affect many users of the browser or will result in power improvements that are not site-specific.

The main list of power related bugs is available on this Bugzilla page. Please note that it mixes desktop, mobile and Firefox OS bugs.

Mozilla hopes to reduce power usage in all versions of Firefox by addressing these bugs and implementing new power saving methods in the browser. The organization notes that doing so may also have an effect on performance as fixes may result in lower cpu usage among other things.

Developers and Firefox users who are interested in this new project can check out the official discussion mailing list (archive) over on Google Groups.

Closing Words

All recent benchmarks show that Firefox could do better when it comes to power consumption, and that's exactly what Mozilla aims for in Project Candle.

Mozilla plans to reduce power consumption of Firefox
Article Name
Mozilla plans to reduce power consumption of Firefox
Project Candle is a new initiative by Mozilla that aims to improve the power consumption of the Firefox web browser on all supported platforms.

Tutorials & Tips

Previous Post: «
Next Post: «


  1. LimboSlam said on September 20, 2015 at 10:28 am

    Now I wonder if Pale Moon has any of these bugs? Yeah I don’t quiet understand the Bugzilla stuff.


  2. mikef90000 said on September 17, 2015 at 2:31 am

    My dual CPU Celeron isn’t the fastest but I often find web sites that have buggy, twitchy, power consuming javascript code; it doesn’t matter which browser I use. I attribute this to a CMS generating pages badly or a web designer who just doesn’t care. Noscript is my friend :-).

  3. webfork said on September 16, 2015 at 8:29 pm

    I’m very glad this is getting highlighted. I wouldn’t mind seeing more tools like this showing the lowest CPU usage by a player or codec. Maybe tools for turning off non-essential system operations and the ability to easily or automatically dim or turn off a screen? These vary widely depending on the manufacturer. For example, my ThinkPad has a loads of nice power settings to tweak but unfortunately the interface for them is rather convoluted. Meanwhile my Mac has some nice automatic features but few manual controls for extending battery life.

  4. lolz said on September 15, 2015 at 7:17 pm

    disable javascript, image animations, flash, disk cache – problem solved.

    oh, and they need to remove XUL too, its too power consuming.

    1. Pierre said on September 15, 2015 at 7:46 pm

      Yes, disable use of internet too
      And use of computers.
      Phone as it existed in the 50ths and paper and pencil were enough

  5. Pierre said on September 15, 2015 at 5:05 pm

    That’s right, Chrome is the worst.
    Why don’t they mention Edge ?
    The worst is Linux !! (sorry, GNU/Linux…)

  6. El Goopo said on September 15, 2015 at 4:33 pm

    To me it looks more like an attempt to group together bugs related to excessive power consumption, and prioritize them. Not everything has to be some marketing conspiracy. Some people genuinely care about how long their device’s battery will last as they casually browse the web.

  7. Maelish said on September 15, 2015 at 3:41 pm

    Power consumption? My first reaction was that they planned to slow the browser down to save electricity.

    But I have to ask, is this a case of just relabeling a large swath of bugs to sound eco-friendly? Not merely the ones that actually might matter in this case but a quite a few others just to look good?

  8. Chris said on September 15, 2015 at 10:04 am

    Something’s wrong with that bug list. It gives me more than 500 bugs, mostly unrelated.

    The wiki page has proper lists.

    1. Martin Brinkmann said on September 15, 2015 at 10:09 am

      Chris, that’s strange. I have fixed the link I think, can you please try again?

      1. Chris said on September 15, 2015 at 10:10 am

        Thanks, now it’s OK.

Leave a Reply

Check the box to consent to your data being stored in line with the guidelines set out in our privacy policy

We love comments and welcome thoughtful and civilized discussion. Rudeness and personal attacks will not be tolerated. Please stay on-topic.
Please note that your comment may not appear immediately after you post it.