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1,148 reviews for this add-on
  • No longer works on Youtube. Even though it prevents the video from showing, it's still running - and gobbling up data.

  • Does not block sound. No switch on/off

  • Only the video features are blocked not the audio. So when I tried to turn the audio off - I couldn't!! Worse than non-functional.

  • No way to toggle on/off; if there is something (YOUTUBE, for example) that you want to see, you need OPTIONS, ADD-ONs, Disable FLASHBLOCK, Reload FIREFOX. Then after viewing, OPTIONS, ADD-ON, Enable FLASHBLOCK, Reload FIREFOX. Sure would be nice if they'd roll back to the version that actually worked as intended....USED to be a nice product.

  • Good functionality, but it doesn't support the modern firefox feature -- multi-process usage to effectively distribute the load.

  • On Youtube, it replaces the video with the button like it says it will, but it doesn't stop the audio; then when I try to get the video to play by clicking the button I just end up with a loading icon. This used to work great, now its completely useless.

  • The addon is fine but there is quite a number of cases where I have to turn off flashblock as a whole in order to visualize a page or a site. This is quite annoying because the command "allow flash from this site" should be enough. Well, better be safe than hurt but still ...

  • Leider blockt flashblock die zugefügten Ausnahmen.
    Vielleicht ein Bug ?

  • Are you working on e10s compatibility, Philip?

  • Flashblock successfully blocks all autoplaying videos, and that's great. I can open multiple tabs on sites that autoplay, without nervously rushing to pause the videos on the new tabs before they make my PC unresponsive.

    Unfortunately, it's not so great at letting them start. While most of the time there are no problems, some things can't be used at all with Flashblock enabled, some require multiple refreshes, and some need perfectly timed clicks on the FB play button after a refresh before something else loads and blocks the video from starting completely.

    In any case, there's a very good workaround - move the Flashblock toolbar button somewhere convenient, and use it to disable the extension when something can't be started because of it. It only works on reload of the page, which means any other open tabs won't be affected and suddenly start playing. But it also means you have to reload the page you're on, and you have to remember to re-enable Flashblock afterwards. Still, it's the most convenient option we have available.

    And a note to people who experience a particular problem on YouTube - the video starts playing anyway with sound only on a black screen, and the visuals can't be started at all. Make sure NoScript is not installed (or just inactive?). It's right there in the description, and I had the same problem until I uninstalled NoScript.

    Finally, since HTML5 seems to be the source of much of Flashblock's woes, I recommend unticking "Block HTML5 video as well" in FB's options, using Firefox's built-in function instead - in about:config, set "media.autoplay.enabled" to false.

  • NoScript Security Suite
    by Giorgio Maone

    you can block anything on YT, more options

  • the rest worked well in the beginning but now has too many issues

  • more and more problems. plugin practically doesn't work. earlier it was super, but no it is hell. i'm uninstalling it. one star

  • Данное расширение не работает почти на версии Firefox 38.0. На версии Firefox 43.0 происходит окончательный крах. Плагин можно ставить на версии лисы до 33.0-35.0

  • I have used this add-on for several years, but since the beginning of 2016, it has become ever more problematic, especially with YouTube videos. Seems like every time either Firefox or Adobe Flash issues an update - which feels like every other week - one or another of my Firefox add-ons gets broken, and FlashBlock is sadly one of these. YouTube videos always start with just the Audio playing and the video window blacked-out. I hit "reload", and get an error message that "Flash Player has Crashed", or "Flash Player Cannot Open the Video Stream", then I hit the "reload" button a third time, and the video will (usually) finally play, with the audio in sync. If I re-start Firefox with FlashBlock disabled, all the errors go away and YouTube videos start and play correctly first time, every time. So it looks like FlashBlock simply doesn't work properly anymore with the latest versions of Adobe Flash and Firefox.

  • Though when it works it is nice - functionality is great - but when it doesn't work, you're left guessing how to make it work. Sites use subdomains and CDNs to deliver content, which are usually hidden behind layers of code that even me as an occasional web coder can't figure out. Every time a site updates you have to whitelist a new URL.

    A nice feature to improve this would be one that does this work for you, you should just right-click and click 'whitelist' and the plugin will determine where the flash content is being served from.

  • Super weg mit der nervigen Video-Werbung !

  • On certain sites the button does appear, but the autoplaying videos play regardless only with sound. Clicking the button does not load the visual part. On other sites the button is not clickable, i.e. video won't start after clicking it.

  • 1) Could you please make the video thumbnail be shown, instead of a black screen?

    2) A shortcut to play the video would be nice, instead of having to click on it.


  • First the bad: The Icon is too pale (orange) and looks "grayed-out" (inactive) to me.

    The good: Using it to control HTML5 Video in Pale Moon (Now mostly no longer using Flash). Had to set "media.autoplay.*" "about:config parameters" to stop sound play. To watch a video: Push flashblock icon, reload page, click on video "seek bar" to start.

  • Old version about a year ago worked Great now this has gone down hill it will still auto play flash links just not display anything will loading and stealing bandwidth, on top of that when you try to watch a flash 99% of the time you have to hurry and click the unblock button other wise it will never load been fighting with this and no point in using this since it really only blocks the display of the video playing but not the loading part like it use to, on top of that fighting to watch videos I do want to watch isn't worth the tons of my wasted time it has caused being buggy and lame

  • It's too bad!

  • This plugin will make it so that you're required to use flash to view Youtube videos and such. Ah the irony. Thus 1 star untill it's fixed. Youtube started working with html5 after I disabled to plugin like someone adviced on forums.

  • webm (html5) audio doesn't get blocked on a lot of websites what gives me jump-scares all the time, please can you fix your addon cause there's no alternative to Flashblock. Thank you.

  • Didn't work very well; problems from the get-go and documentation didn't resolve them. Anyway, more bother than dealing with flash, at least at this point.