About QuickJava

QuickJava is a Firefox extension that allows you to easily enable/disable Java, JavaScript, Images, Flash and more directly from the toolbar and/or status bar! (Need help?)

Sunday, December 31, 2006

About the QuickJava Plugin

QuickJava is a Firefox plugin that allows you to easily enable/disable the Java and Javascript from the toolbar. Two icons are placed in the toolbar, click on them to toggle the state. If you right click either icon it will update both icons.

The QuickJava plugin can be found here.

Version History:
0.5 - FF 3.6 Update by xxhatred
0.4 - Middle-click either icon to toggle both preferences.
0.3 - Automatic update of icon even when preference is changed elsewhere.
0.2 - Added graphics, other minor tweaks.
0.1 - First version: Internal version only

This is my first plugin and I'm still getting a feel for how to do everything.

Please feel free to comment and post requests.

Plugin Developed By: Doug Greene
Graphics Developed By: Kate Tarvin and Doug Greene

(Yes the date on this "blog" entry is way into the future, to keep it up top)


  1. Hey there,

    Why havent you upgraded your extension to support the new version of firefox???

    I just love your extension man...

    Makes life a lil bit simpler...

  2. There is an updated XPI file via the comments that another user supplied, however when I tried to upload it to the extensions site I got an error about invalid min and max version (the min version has not changed). I've got a lot of stuff going on with school and work right now, I'll try to figure it out after I'm done w/ school.

    Thanks for the appreciation.

  3. I think I know now, why the uploading of the new version failed. I found the following Website:


    which explains about extension-versioning and I believe replacing maxVersion-value "1.5.0" with merely "1.5" should do the trick. This update is know included in:


    (same filename as before)


  4. Tolles plugin!

    Gibt es ein update für firefox 1.5?

  5. Thanks for the update Daniel, I submitted it for approval.

    Sorry if it took me a while guys, I didn't get an email notification for that (and some other) comments, guess now I know not to wait for them.

  6. Thank you for this great extension. It´s exactly what I was looking for. It works perfectly, but an option to place the buttons on the toolbar would be very usefull, because they could be easily overlooked down there on the status bar.

  7. can't get this extension to download into v1.5 for anything -- keeps telling me that software downloads ar blocked (which, as far as I can tell, they are not) -- have tried it several days in a row

  8. Are you trying to install it using the "Install Now" on this page:

    If you aren't then try that... if you are then add the site to your approved list (It's been so long I don't remember, but I thought it was automatic for the mozilla site). If it's an external notification and not the firefox notification then check software firewalls or anti-spyware programs will often disable direct installs.

    Another option is to try a local install, which I think can be done by saving the file (Right click "Save Link As" on the "Install Now") then drag the file onto the firefox browser window.

    Good luck.

  9. OMG - Your plug in if it works as promised (I just downloaded it) is a godsend to all surfers. All too often I've been forced to sit as various java applets I don't want and didn't request are loaded and started when I visit a particular site or while I'm exploring.
    Java' slow execution is the #1 generator of "false alarms" in regards to computer malfunction.
    Thanks, I can't wait to start using this applet. (ironically it is a java applet isn't it :)

  10. How do I use it? I click the install icon and nothing happens. Are there installation instructions anywhere?

  11. In response to "how do I install it":

    When you click the install on the Mozilla Extensions - QuickJava site, if nothing happens check the top of the browser window (just below the tabs (if activated, otherwise below the bookmark bar if activated, otherwise below the URL bar) to see if a notice about installing comes up. You may need to add mozilla.org to your trusted sites to install software off of it.

    Then a box should pop up asking if you want to install (ther will be a delay before you can click OK). After it installs you need to restart firefox (close all open Firefox windows, then start it up again). After that there will be two new icons in the status bar (see the screenshot on the mozilla.org extensions site linked above to see what the icons look like). Obviously to see them you need to make sure your Status Bar is enabled under the View menu.

    Good luck.

  12. Thanks, but that's all Greek to me. ;-) All I know is I click on the installation button and there is no result. No questions. No dialogue boxes. No action of any kind. I tried downloading the installer and clicking on it from my desktop. Same thing - nothing.

  13. Let's take this to email... contact me at "Doug" then "07162" then "@" followed by "gmail.com".... put it all together (trying to avoid spam).

  14. Great extension, couldn't browse without it.

  15. Great tool! But it would make things easier if the icons were placed on toolbar as regular checkbox buttons (no graphics).


  16. It would be nice if QuickJava had a whitelist feature.

  17. I have installed your extension - very useful for Java but less useful for Javascript, if somebody uses NoScript, because your extension overrides NoScript, which gives a more granular control. So i wish, that you provide an option to use the Java/JS blocking functions separately or incorporate NoScripts functions :) So long i will not use it, because i need a good control over JS much more than for Java.

  18. I have the Leak Monitor extension installed
    and it sometimes detects a leak in QuickJava 0.4.1 when I close a page. Here is the log:

    [+] [leaked object] (2cd08c0) = [object Object]
    [+] register (2cd08c8, chrome://quickjava/content/browserOverlay.js, 114-119) = function () {
    var observingPrefsActive = false;
    var prefService = Components.classes['@mozilla.org/preferences-service;1'].getService(Components.interfaces.nsIPrefBranchInternal);
    this._branch = prefService.QueryInterface(Components.interfaces.nsIPrefBranchInternal);
    this._branch.addObserver("", this, false);
    [ ] prototype (1edca80) = [object Object]
    [+] unregister (2cd08e0, chrome://quickjava/content/browserOverlay.js, 124-126) = function () {
    if (!this._branch) {
    this._branch.removeObserver("", this);
    [ ] prototype (1edc888) = [object Object]
    [+] observe (2cd08e8, chrome://quickjava/content/browserOverlay.js, 130-142) = function (aSubject, aTopic, aData) {
    if (aTopic != "nsPref:changed") {
    switch (aData) {
    case "javascript.enabled":
    case "security.enable_java":

  19. I can recreate this problem with many pages, even the default Firefox search page. All you need to do is open a new window in Firefox, then close that window. Opening and closing tabs doesn't seem to trigger the leak (or at least Leak Monitor 0.3.0 isn't detecting it.)

  20. Great extension!

    I would like to see a third button "F" there for quick disable/enable Flash. Then it would be perfect!

  21. Hi,

    QuickJava fails to install on Firefox (which was released today).
    Firefox claims that QuickJava is incompatible with this version...

    Could you fix this ?
    Thx a lot in advance !

  22. Hi,

    It also fails on FF

    Will you have a fix soon?

  23. The Update on Version 0.42 is faild. Its the same Problem as last Version. But here is the Fix.

    In the Original install.rdf is the following String:



    The right String for a right Installation is so:


    And evrething works fine ;-) !


  24. hey man thanks .. i have uninstalled No Script. and now im using QuickJava. i love it .. it is less hassle free. it should be on the top extensions list. simply awesome. and thanks for uploading it on rapidshare.

    it works on latest firefox build
    i hope Doug will update it on Firefox addons page cause it didnt work for me there.

    anyways great extension and keep it updated. simply love this extension.

  25. Please correct install.rdf:
    wrong: 1.5.0.*
    because "*" is interpreted as an infinitely-large number.
    (see http://developer.mozilla.org/en/docs/Toolkit_version_format)

  26. Hey guys, I corrected the install.rdf file yesterday and uploaded it.

    I was trying to push it through quicker in the IRC rooms but I'm guessing nobody heard my plea for help.

    Thanks for the input and support, I really am amazed by how many people LOVE this extension and it feels great :)

  27. Really great how quickly tou responded to the error in install.rdf!

    I would miss this extension very much if it would not be updated anymore.

    One note: in the quickjava- there is a file which is not needed I think: Thumbs.db, and an folder not needed: _macosx\chrome, maybe leftovers from when you worked on it.

    I have a request too, if it would be possible, it would be great: to make bookmarklets (bookmarks starting with javascript: instead of http://) work even if Javascript is disabled (if that's possible at all).

    Thanks for such a great extension which should have been in Firefox by default! (Combined with Plugin Manager at http://www.gozer.org/mozilla/extensions/, that would be most ideal).

    Have a very nice day :-)

  28. Unable to install QuickJava in Firefox Win32. "Invalid file hash (possible download corruption) error." I unzipped the .xpi file, no apparent problems; rezipped it and still get same installation error. Any advice?

  29. Re: Invalid Hash

    Hmm, unless others start complaining about the problem I'm guessing that it's just on your end, and I'm really not sure... I would clear the downloaded cache from when you DLed it the first time and then try to install it from the site again which may fix the problem. Other than that, you may want to try looking through the FF support forums or IRC channels.

    Good luck.

  30. This comment has been removed by a blog administrator.

  31. Hi all,

    if you want to know more about java and the latest news log on to javaworlds.blogspot.com
    Great work Firefox

  32. Very useful extension that worked fine until recently. I can't say whether it is due to an update of this extension, or the installation of an incompatible extension, but whenever I open a new window I also have to set the java/script preference by hand; the extension shows a third symbol that clearly asks for manual setting. If this is a feature, I would like it to be removed.

  33. Re: Third symbol

    There are only two icons (J and JS) added to the status bar, each icon has 3 possible states:

    Enabled( ) - Just the symbol icon
    Disabled(/) - The icon symbol w/ a slash
    Unknown(?) - The extension was unable to determine the setting.

    Have you installed any other extensions lately?

    I am unaware of any problems with other extensions that are incompatible due to the lack of complexity of this extension, however it is possible. You may contact me at Doug then the numbers zero,seven,16 at g-mail (remove the dash) dot com. Please let me know what version of FF you are using and a list of your installed extensions.

  34. great extension, but simple problem: you have chosen to show the disabling of javascript and particularly java by drawing a red slash through the icon.

    drawing a red slash through the "J" java icon makes it, essentially, unreadable. there is a bit of the top of the J and a bit of the bottom.

    i would like to install this on some newby friend computers, but an unreadable J with a slash through it isn't very helpful.

    how about a quick adjustment to those icons for readability?

    what about, for example, leaving the blue circle with a white J when java is ON; but when java is off, how about a white J on a blue square background with a big red "X" that goes BEHIND and UNDERNEATH the "J"?

    anything would help instead of just overwriting the J and JS with a slash that obscures them; thanks

  35. my same comments apply to the "JS" icon even though I didn't mention it specifically; please consider a better way to signify "OFF" instead of overwriting and obscuring the same icon you are trying to use to communicate to the user;
    remember, also, that people may have *many* icons; if everybody who made a plugin turned them 'off' by obscuring or messing up the original icon it wouldn't be a very pretty situation

  36. Anonymous:

    Please feel free to submit graphics if you feel you could do better. I am (obviously) not very good at graphic design.

    (You can upload them to one of the free file upload sites such as megaupload and just post a link here)

  37. Installing Firefox on my sister's computer for her and QuickJava has vanished from mozilla website. I consider it a "can't get on the web without" and wonder what has happened.

    Hope it is a temporary condition!

    Thanks ...

  38. It's still on there...


    Hope that helps and thanks for the compliment.

  39. Nice plugin.

    It would be even more useful if it would prompt the user while browsing when a website tries to launch the java plugin, giving the user the option of allowing or denying the action. An option to remember that permission for each site would be even better. Any plans to incorporate any of these features?

    Thanks, and nice work so far.

  40. Would you be able to create your extension so it is similar to the NoScript extension? What I mean by that is this. By default I would like to see both J and JS disabled. Now, if I go to a website and I trust that website, I would like to be able to add it to a "whitelist" in QuickJava so the next time I visit that site it will remember that I want J and JS enabled.
    What can I say, sometimes it is so much clicking, on, off, on, off between sites, that I wish it had this function. Not to mention sometimes I will forget to click both J and JS off and there I am surfing with it on, when in reality I don't want them both to be enabled.
    Just an idea for you though.

  41. Hi there,
    I have been using your extension for a while.
    i recently had to create a new profile and your extension stopped working.
    I now have the two icons in the status bar with a red question mark upon them.
    I have verified trough about:config that if i click on the icons the status of the application does change but not the icon display so there is no way to know if the effect took place or not (unless you get into config but that defies the purpouse of your extension really).
    Let me know if you want a list of my extensions to look for conflicts but I would probably need an email cause I have many.
    Take care


  42. Threshold,

    Can you please try uninstalling the extension and then re-installing it, and let me know if that fixes the problem for you.

    -Uninstall it, restart firefox (make sure ALL of your firefox windows are closed, including the download windows and such)
    -Load firefox, re-install extension
    -Unload and reload firefox to complete installtion
    -Does it work?

    Let me know, you can email me at [putmynamehere]07162[the-a-sign]gmail.com


    (Technical, option reading)
    Think of firefox as having a hook labeled "this event happened" that gets "pulled" when an event happens. When the extension loads, it ties a string to that hook, so when that string is pulled (the extension is loaded) it updates the icons. It sounds as if, this is not registering properly.

  43. I run Windows XP and have the latest edition of Firefox. I downloaded QuickJava but it didn't work. I tried to download it and install it again in case there was a problem the first time. The two little icons are there but they don't do anything. Nothing happens whether you right click or left click. The icons merely sit there and take up space.
    Very disappointing, too bad.

  44. Jättefin liten grej du har gjort där! Taxlar så myxla :-)

  45. Where is the source code?

  46. A Shortkey for Javascipt On/Off would be nice.
    Thanks for this plugin!

  47. Firefox 3.0b has been released!
    We are waiting for now a new version of your program.

    I think that this program is more intelligent, simple, useful than noScript!

    Simple is beautiful!
    This is an engineered plugin!

  48. Hello,

    thanks for this very usefull plugin. It worked fine until now. Every time I started firefox, the extension shows a questionmark over both symbols. Regardless of the last setting.
    It´s a new setup, firefox, QuickJava I tried uninstall, reboot, new install. But it´s the same as bevore.

  49. Hello,

    first, thanks for this Extension. But I have a little problem here with it: It appears to do nothing, just as "anonymous" stated at 9/28/2007 10:08 PM. Whenever the icons are clicked, they remain unchanged. Later I found out that they do in fact change the settings, they activate/deactivate Java and JavaScript in the Firefox Options as they should, only the icons don't change, so I cannot see if Java or JS is currently on or off.

    Can that be a conflict with another Extension oder my theme? As Theme I use BlueShift, and I have quite a larger number of extensions installed. But I just switched back to the Firefox Default theme, which didn't solve it.

    I also noticed this behaviour on several operating systems, both FF on Debian/Linux and FF on Windows XP, both with more or less same setup and extensions.

    So, if this is an easy one, any hint or help would be appreciated. :-)

  50. Doug, great extension, simple and sweet. Thanks for your effort. Is it hard to create an option that would a) only display one of the two icons? And/or to display them as a toolbar button instead of a status bar button? Thanks again.

  51. thx for the plugin...


  52. In case nobody else has pointed it out: this doesn't work with FireFox 3.x. :(

  53. I've tested "QuickJava" in the latest nightly builds of Firefox 3 (simple function, unbelievably useful). So far, no problems and I don't foresee any problems in the future except for one. Currently, it's "not compatible" and cannot be installed in any version of Firefox 3.

    Could you please do a final compatibility check and update the "install.rdf" file so that the plugin can be installed in the various Firefox 3 builds? I believe that just changing the max version to 3.0.0.* should do the trick.


  54. WIll you make it for FF3, because it is really useful addon.

  55. Can you add a toggle for the new f3 addons manager way of disabling flash?

  56. Not sure if this blog is still read, since the entries seem to be dated. But in the off chance it is, I would like to make a suggestion.

    First off, I love this app. It is one of only two plugins I use for Firefox.

    That said, can you please consider adding a timer option that a user may chose for disabling javascript?

    For example, when I log in to Yahoo mail I have to switch settings to allow javascript. At times, I forget to switch javascript protection on again after logging out of my email account.

    Perhaps by allowing the user to set javascript off by a timer, let's say for two minutes, then javascript protection will automatically switch back to active without further user effort. Before logging in to my email account, I can set it and forget it.

    Just a thought. Thanks.

    P.S. Similarly, a Firefox plug in like this for cookies, as well, would make sense for any future app designers.

  57. I too would like to see this extension updated for FF3. Thanks for a great product

  58. My icon on statusbar have question mark. I use Firefox 3.0.4 and Quick Java

    Any solution?

  59. Hallo,

    would be nice to have an update for FF3.1 (Beta 2)!!!It's still one of the handiest tool for Java.
    Thanks, Vincent

  60. Hey..:(..

    I feel like a moron..but i can't seem to get this to work..Every time i want to zoom or a window[picture]-say on ebay to get a closer or larger view..Or if on Utube..and i want to change something..it tells me i have Javascript disabled..? or not installed..
    I have installed this..yet i see no icons to disable/enable JavaScript..It's driving me nuts..
    When I click on something to zoom..You see in the bottom left corner of status bar..
    Javascript: void (0)..

    Can u please help me..
    I'm using Firefox, 3.5.2 the newest version i believe

    Help please..!~ ':((

  61. Oh wait...I see now where the buttons are...and there are NO lines through them..and yet still doesn't work...:(

  62. Oh ok..I have seen all comments now..I gather it does't work with FF 3.5.2...Darn...I'm really beginning to get pissed at the new FF...a few things..are haywire about it..!..

    PLEASSSE make a new version...for without this..I can't zoom in on pictures or anything on certain sites...like how is it that i can only depend on this plugin...to view certain websites..with Javascript..ect..



  63. mercedes,

    I'm not sure what you're having problems with, but I just tested QuickJava with 3.5.2 and it works fine.

    All QuickJava does is turn the javascript (or java) on and off at the browser level. You can do the same thing by going to Tools->Options->Content and check/uncheck the enable javascript/java.

    As long as my control changes with these values, it is working properly. Any further problems you're having are not as a result of my control and I can't help you with them, sorry.

  64. i am getting this message every time i connect to the internet what does it mean, i have tried everything
    Exception... "Could not convert JavaScript argument arg 0 [nsISupports.QueryInterface]" nsresult: "0x80570009 (NS_ERROR_XPC_BAD_CONVERT_JS)" location: "JS frame :: chrome://searchshield/content/overlay.js :: InitSDK :: line 410" data: no] win adamson

  65. Win,

    That error is unrelated to this extension. Based on the information you provided it would seem to be a problem with "searchshield", which I think is part of the AVG Anti Virus package.

    Past that, I'm unable to provide you with any more help, sorry.

  66. option to only show one button or another

  67. How come the current version on AMO (addons.mozilla.org) is said to work with Firefox versions up to 3.6a1pre and a developer comment there says it has been tested with Firefox up to 3.5.3 (and a recent comment on this blog says 3.5.2), when version as found on AMO in reality has a maxversion of 3.0a1 ?

  68. The "maxversion" of 3.0a1 was the last time I actually had to upload it. The blog says 3.5.2 because I have personally used it on that (well, now 3.5.4).

    I set it to 3.6a1pre because I have not had to make a change since August 3, 2006, which was only because of a major change in Firefox (to version 3) so I am pretty confident that it will work.

    This extension is VERY basic and is only tied to core components of the browser, so I don't expect it to stop working unless those core components are changed, which would only likely happen in a major version release.

    That said, are you having problems?

  69. I have learned that when the maxversion is updated on AMO, the xpi/install.rdf files aren't necessarily kept in sync with that, and this is instead handled by "a compatibility update has been applied" in the browser.

    So, no problems (anymore), and thanks for the extension, which has been useful to me!

  70. Dude, a priceless feature would be to allow disabling javascript in Background tabs. This would save loads of CPU time to lunatics like me who like to keep dozens of tabs open but don't want to sacrifice functionality of active tab...

  71. Doug,

    Thank you for this extension. It is exactly what I need. Unfortunately I'm having a problem getting it installed on my destop computer (It installed perfectly on my laptop).

    I get an error message saying that QJ is incompatible with FF 3.5.5, even though I'm using the same combination of versions on my notebook.

    Any idea what I can do install this? Thanks in advance for any help you can give me.

  72. Doug,

    Thank you for this extension. It is exactly what I need. Unfortunately I'm having a problem getting it installed on my destop computer (It installed perfectly on my laptop).

    I get an error message saying that QJ is incompatible with FF 3.5.5, even though I'm using the same combination of versions on my notebook.

    Any idea what I can do install this? Thanks in advance for any help you can give me.

  73. BTW, this may help solving the problem reported in my previous post. I also get an error message saying, "Java Plug-in Fatal Error -- several Java Virtual Machines running in the same process caused this error."

    Hope that gives you more info on how to solve this issue.

    Thanks again for your help.

  74. Pat,
    It sounds like you are having a problem with your Java plug in, not my extension. I can't help you with that, sorry.

  75. > I get an error message saying
    > that QJ is
    > incompatible with
    > FF > 3.5.5

    Same with me - maybe using Firefox Portable might be the problem (as I do)?


  76. Wonderful job you've done with this!

    A few suggestions (I'm sure you've heard them all before:)...

    1. a whitelist perhaps? this would be nice!this would allow all sites in the whitelist and block those that are not there in the list

    2. a notification as in noscript when you disable javascript.

    Of course, if these features are going to bloat the addon, then keep it as it is! I like it...very simple!

    Keep up the good work!

  77. Doesn't work with Firefox 3.6
    I've made it 'compatible' with Nightly Tools, but it doesn't turn on or off Java.

    The way plugins work has changed with Firefox 3.6

    Maybe you could take a look at it.

    Thank You

  78. Hi,

    I'm a fan of this plugin, too. It would be great to have it in 3.6, too...


  79. Nice to meet you.

    I'm Japanese.

    Thank you for the useful plugin
    to Malware like Gumblar.

    In the next version,
    I hope for additional functions
    that disable "iframe" and
    "embed objects such as WMV,WMA,Flash"
    while keeping QuickJava's simple interface.

  80. Satisfied user1/21/2010 12:01 PM

    Hi !

    Great extension. Please upgrade it to be compatible with FF 3.6 just officially released today !

  81. Satisfied user1/21/2010 5:30 PM

    Hi again

    Actually, by bypassing the compatibility check, the Javascript switch does work, but not the Java switch - Too bad... :-(

    So, we need an update.

  82. hi Doug

    with your Quickjava adds to Flashblock, Adblock Plus and Ghostery
    is a perfect combination team.
    as soon as you have your Quickjava compatibles to FF 3.6, i would get rid off NoScript right after i re-install the perfect combination team.
    please help and thanks much

  83. Anybody has any news about updates for 3.6?

  84. Great plugin, thanks! Hope to see a 3.6 compatible version soon though...

  85. I love this extension. When will we have an update for it?

  86. This is one of the best extensions ever and many of us don't want to use NoScripts thingies.

    Please, update it for FF 3.6

  87. please please update to firefox 3.6

  88. Thx for the great plugin!

    Please, make it for firefox 3.6!


  89. I have to echo sawai's comments, love the extension but wondering what's taking so long for the 3.6 compatible update?

  90. not compatible with ff 3.6 :.(

  91. Sorry about the delay. A version for FF 3.6 has been developed by xxhatred and has been submitted for review. This version should be available shortly.

    Also, if you'd like to submit new icons for future versions please see:

  92. Hi,

    I've been using your add-on for years, and everything works fine, except in 1.7.2 Java provided by IcedTea6 (that is OpenJDK) cannot be blocked. IcedTea6 starts regardless of the button setting.

    Thanks a lot for the work

  93. LMB, Since Firefox changed how the Java works it's no longer just changing a setting. The program has to try to figure out which plugin to disable. As such, the extension works with the default Sun Java. If you are using a different Java runtime you will need to modify the extension and change the regular expression to one that will match the runtime you are using. Since I don't have it installed I won't be able to help you any more than that.

    If somebody does post a regular expression that works for the default Sun Java and IcedTea6 at the same time, I may look into incorporating it into the next version.

    Sorry I can't be of more help.

  94. With the help of QuickJava - Firefox add-on, you can easily permit or prohibit the execution of Java or Javascript in your browser.

  95. I like your Add on i have used this to solve my problem of opening Heavy HTML files. I will soon writing a mail to let you know some good stuff.

  96. Please please please make a version of this for Chrome :)

  97. How do I stop this page appearing every time I start Firedox

    1. The page should only start the first time you install the extension or when a new version is updated and has major changes. If it is occurring every time you start Firefox then please make sure you have the latest version of Firefox and the latest version (48 or newer) of QuickJava (2.1.0). If it still happens please try the steps on this page and report back with your findings by opening an issue on the GitHub page (link in the sidebar at the top):


Comments may not be read by the post author. Please use the links in the sidebar to find the GitHub repository to submit suggestions or bug reports.