Adblock Plus and (a little) more

Faster Firefox startup · 2014-03-14 22:54 by Wladimir Palant

We’ve received lots of complains over time about Adblock Plus slowing down Firefox startup considerably. It’s not that we didn’t listen but this is really a tricky problem. However, Brian Nicholson from Mozilla pointed out that there is a relatively simple solution and this solution has been implemented now. Starting with Adblock Plus Firefox seems to start up almost as fast with Adblock Plus as it does without. The only disadvantage should be that Adblock Plus is ready a bit later and the first page loading might still have ads.

Now to the scary part: in theory, this change might cause data corruption. So if your filters suddenly get corrupted (only some filter/filter lists load), please let us know.

To the install page


Comment [17]

  1. Charles · 2014-03-15 01:01 · #

    A great news, certainly. But will it be optional? Some hidden preference? I feel that ads in the first loaded page can be more irritating (depending of the case) that the slower loading; I don’t care about the latest.

    Reply from Wladimir Palant:

    No, this won’t be optional – delaying Firefox startup isn’t great. There is no real change here, ads were already showing up on the first page under some circumstances. This change only makes it somewhat more likely.

  2. Arthur · 2014-03-15 12:09 · #

    Great to see improvements there!

    The first issue I noticed is that filter subscriptions that were enabled now tripled in the filter settings (EasyList shows up 3 times e. g.). In another profile also disabled subscriptions were duplicated. This also happens in a fresh profile after some restarts. I used FF 27.0.1 in both cases.

    Should I file a bug report for that?

    Reply from Wladimir Palant:

    Thank you, looks like we missed something there. Feel free to create an issue report for that, otherwise I’ll do it myself.

    Reply from Wladimir Palant:

    Never mind, done:

  3. mapx · 2014-03-15 12:28 · #

    I confirm the duplication of the lists and also of the groups of custom filters

  4. tal · 2014-03-15 15:08 · #

    Yep, I getting the duplications too.

  5. Arthur · 2014-03-15 18:32 · #

    Another weird filter issue I got:

    Some weird filters were added to Fanboy’s Social Blocking List.

  6. chuggerguy · 2014-03-16 08:36 · #

    It might be nice if general subscriptions such as Easylist were not loaded at startup BUT either a “Load First” type custom list OR some sort of “Smart List” that pertains only the browser’s current home page were loaded at startup.

    If done using some sort of “Learning mode?”, ABP could automatically determine which filters were, at least at the time of determination, needed, and saved to the starup filter list.

    Just an idea, probably asking way too much. :)

  7. mapx · 2014-03-17 12:08 · #

    user report:

    Sadly it’s not working as good as advertised. With Adblock Plus startup time (“firstPaint”) is still Adblock 4217 ms (mean value over five startups).

    Here’s the comparison to the values with the old ABP and without ABP (values copied from above, but checked to be still valid):
    2386 ms mean (over 5 startups) with Adblock Plus disabled
    4217 ms mean (over 5 startups) with Adblock Plus enabled (2.5.1 build 3778)
    5599 ms mean (over 5 startups) with Adblock Plus enabled (2.5.1 stable)

    Therefore ABP still slows down Firefox startup by about 77 %! Additionally with the new build there’s a lag (Firefox becomes unresponsive) of 1-2 seconds shortly after startup; probably the work saved at startup is just done after startup now.

    I’ll be looking for further updates and I hope it will eventually be possible to further tweak ABP to reach reasonable startup times while maintaining responsiveness after startup since this is the only real downside of this wonderful add-on!

  8. André · 2014-03-18 16:34 · #

    For me it slows down Firefox start extremely. Firefox is frozen for 10s (ghost window) under Windows 8 at start and uses a lot of CPU.

  9. mapx · 2014-03-18 22:02 · #
    the same user reported (using build 3781)

    “the lag after startup seems to have been a result of the duplicated filters issue (#152)

    With the newest beta ( and after deleting the duplicated lists I can’t notice a lag anymore.

    However startup time is still not “almost as fast as without Adblock Plus” as stated in the relevant blog entry. A fresh test with the new Firefox 28.0 on Windows 7 ×64 with ABP revealed startup times (“firstPaint”) of
    2488 ms mean (over 7 startups) with Adblock Plus disabled
    5703 ms mean (over 6 startups) with Adblock Plus enabled

    Therefore a slowdown of 130 % which would be nearly as bad as before the changes to startup behavior…”

  10. André · 2014-03-19 08:17 · #

    thanks for the hint about the duplicated lists. I had 20 EasyList Germany entries! I removed the dups and the freeze at start is gone.

    Reply from Wladimir Palant:

    You could also restore a backup now that the issue is gone.

  11. merfius · 2014-03-20 14:35 · #

    wow, I never would have thought to check my filter lists, but I have a ton of duplications as well.

    I’d love an about:config pref to configure how long ABP waits before initializing. The ad appearing on Google then disappearing is quite jarring and has led to me entering some risky sites (e.g. Google “Firefox”, and the first link is an ad to download “Firefox 2014”, presumably some malware — and those who don’t notice the yellow badge or quickly Tab+Enter into results may be susceptible to infection).

  12. merfius · 2014-03-20 14:44 · #

    Also, a way to select multiple filter subscriptions via Ctrl+Click and Shift+Click would be nice — I had 40 EasyLists that I had to delete one-by-one.

  13. Stunned · 2014-03-24 02:39 · #

    Delaying Firefox startup may not be great, but ABP not working as expected and exposing people to not only ads but security and privacy threats is not great either.

    If you want to support a faster startup option that puts users at greater risk, so be it. However, users should have the ability to make the trade-off decision for themselves. While you work to completely eliminate the faulty ABP behavior shortly after startup of course.

  14. Graham · 2014-03-28 01:02 · #

    Agree with Stunned above. I’ve never really cared for the slowish start-up speed (and I’m using an Intel P4 with 1Gb of RAM, which takes ten or so seconds for Firefox to load), seeing that I only start up my browser once or twice a day. I’d rather than less of a chance of an advert to get through and no chance of a filter corruption than a start-up speed increase which’ll possibly shave off only ten or twenty seconds a day for me.

    Please give an option to restore previous behaviour.

  15. neal · 2014-03-31 17:54 · #

    I dislike this also. I have Chrome and Firefox installed, and the only reason why I made Firefox the default browser was exactly b/c it blocked ads immediately.

    Beside the obvious application of homepage ads, there are many instances where a computer action will open up a page. Example would be uninstall surveys. Opening links is another.

    Firefox ABP made sure that whatever opened, it was blocked right away which is huge from a security point.

  16. Nik · 2014-04-09 17:28 · #

    Finally! It works, even tabs opens faster!
    But on slow netbook with Atom freezing until the Adblock icon appears.

    There is something wrong with link, because I could not download completely, only 16kb, tried in the IE, same thing. But Download Master.after been downloaded successfully

  17. Mirko Ce · 2014-04-24 17:46 · #

    Thank you very much! I went back to Firefox thanks to this! Cheers

Commenting is closed for this article.