Mozilla: no more animated themes in Firefox 18

Martin Brinkmann
Dec 12, 2012
Updated • Dec 12, 2012

Are you using Mozilla Personas to install custom themes in the browser or maybe even an add-on like Personas Plus that gives you greater control over the built-in feature? If you do you may have noticed that your browser's start up time has increased after installing a custom theme.

Mozilla recently began an investigation of the issue and found out that Personas theme use large header and footer images to accommodate for large resolutions. Header images for instance need to be in 3000x200 resolution and footer images in 3000x100 resolution, even if the system the images are used on is connected to a monitor running on a lower resolution.

So, even if you are running Firefox on a 1024x768 monitor Personas will load the larger resolution images automatically which is unnecessary and slowing down the start up of the browser. Animated themes are even larger in size and put a strain on the system at all times as they need to be redrawn continuously.

Mozilla's solution is to crop Personas theme images to match the resolution of the computer screen. Cropped images are smaller in size so that it will take less time to load them in the browser.

Mozilla notes that the cropping impacts animated themes which will stop animating from Firefox 18 on (the version of the browser where the fix will land in). To be totally honest, I did not even know there were animated themes available for the Firefox web browser. Still, some Firefox users will notice that their carefully selected animated themes may not work anymore when they upgrade to Firefox 18.

The developers suggest to use the Firefox add-on Personas Shuffler which changes the Personas theme on every browser load. It is not really the same thing though as it is just switching between themes that you have installed whenever you start Firefox.

A configuration switch to disable the cropping of images would have been really nice, as it would have given users the option to disable the feature to keep using their animated themes.


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  1. b003 said on December 25, 2012 at 6:37 am

    I like the idea but all my tabs n stuff would barely show up. It was to hard to see through.

  2. marius timu said on December 14, 2012 at 2:46 pm

    I used to use Personas,not anymore I find them distracting!

  3. Ken Saunders said on December 13, 2012 at 11:57 am

    * Tools > Personas > Custom Persona > Edit

    1. Anonymous said on December 14, 2012 at 1:47 am

      testing, testing, testing.

  4. Ken Saunders said on December 13, 2012 at 11:57 am

    ” the team that approves or rejects them is a bunch of backward idiots’

    The team that approves or rejects them are just volunteers that have to follow written policy. I used to be one.

    In the beginning, there were more complaints from people (like parents) regarding nude and supposedly risque images than those wanting to see them.
    There is no minimum age requirement to view Personas or add them to Firefox, so you don’t want a 6 year old viewing certain things.

    I’m an artists and I’m all for freedom of expression so I understand your side,
    but there would have to be all kinds of things put into place like age verification in order to be able to view and display certain images including classic art.

    If someone wanted to, they could provide Personas on their own site with whatever images that they’d like. I’d image that would very popular.

    There’s also Personas Plus where you can use whatever image(s) that you want. After creating the Persona of course, but that’s cake work.

    Tools > Personas > Preferences > Show Custom Persona in menu
    Tools > Personas > Preferences > Custom Persona > Edit

    1. Threshold said on December 13, 2012 at 8:34 pm

      Thank you for your reply Paul and I apologize if you felt somehow offended by my words but you just ended up confirming my view.

      I am from Italy so I have been exposed to what you refer to as “certain things” since I was a toddler because fine arts is all around me but mostly in, guess what, religious places.

      For whatever reason, despite Firefox being used globally, we have to abide by some puritan morality.

      And I am sorry but if a parent is so stupid to put a 6 yo in front of the Internet by himself, classical art should be the least of his problems.

      If these Personas where so offensive they could have been labeled as containing nudity or worst case scenario restricted by country but I am sorry I have to reinstate that age verification to view ” The Last Judgment ” is, for me, pure ignorance.

      P.s. Thank you for the tutorial but the fun of Personas was also sharing it with others not just myself.

  5. Threshold said on December 13, 2012 at 12:34 am

    I gave up on Personas altogether, after I discovered that the team that approves or rejects them is a bunch of backward idiots, who will ban any fine art themed Persona if it contains any sort of nudity.

    So this cretins have actually rejected Michelangelo, Leonardo, Klimt and all the greatest artists.

    You should go read their forum as it is kinda amusing if you forget for a moment how sad actually is.

  6. Jim said on December 12, 2012 at 11:39 pm

    Well, duh! I could have told them that. I tried an animated theme once and it brought FF to a crawl. Startup took forever.

    The Personas were cool for a while, but I have quit using them. Mostly just forgot they were there. They didn’t add anything useful, so not really worth the effort. I guess they’re okay if you’re into eye candy, but even then, they only show up in the top of the window, which is getting smaller and smaller. I just tried one for the heck of it and I could only see a couple of thin strips across the top. Not worth the effort.

    I agree on the options though. I hate to see capabilities added to software and then taken out. That will always upset some users.

  7. bennix said on December 12, 2012 at 8:21 pm

    I hope this version has no memory leak problem which I am really pissed off…

  8. Ken Saunders said on December 12, 2012 at 6:10 pm

    Since it’s inception (going back to around 2006 maybe “05), light weight themes (formerly known as Personas) have always been 3000px wide. I always thought that it was excessive.
    Creators have been able to use animated gifs, or APNG’s (animatedPNG).

    “A configuration switch to disable the cropping of images would have been really nice, as it would have given users the option to disable the feature to keep using their animated themes.’

    Absolutely true. It’s silly to offer a totally opt-in, add-on feature then remove it for performance concerns/issues.
    If the same logic held true for add-ons, well, there wouldn’t be any add-ons at all and there would be far fewer features in Firefox.

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