Make your Firefox load faster!

Me dad was complaining that his Firefox takes ages to start up and didn’t want to run yet another application in the background.

So I hit google and came up with UPX, Ultimate Packer for eXecutables. What it does, is very simple: It compresses the .exe and all the DLLs associated with said .exe! Thus reducing its total size and load time.

  1. Download UPX and unpack the upx.exe into your Firefox folder, usually it’s C:\Program Files\Mozilla Firefox.
  2. Close Firefox, and make sure its not running by checking the task manager
  3. Start the command prompt, the cmd.exe in ADMIN MODE!
  4. go to C:\Program Files\Mozilla Firefox in cmd.exe
  5. enter this command and execute it
    for %v in (*.dll *.exe plugins\*.dll components\*.dll) do upx "C:\Program Files\Mozilla Firefox\%v" -9

Should you, for whatever reason, need to decompress and get the original files back, run this command
for %v in (*.dll *.exe plugins\*.dll components\*.dll) do upx "C:\Program Files\Mozilla Firefox\%v" -d

What does it do?
It compresses all the DLLs and all the *.exe in C:\Program Files\Mozilla Firefox, then it goes to C:\Program Files\Mozilla Firefox\plugins and compresses all the DLLs, lastly it goes to C:\Program Files\Mozilla Firefox\components and compresses the DLLs in there. The -9 is for the best possible compression. The -d is for decompression.

My dad’s Firefox folder went from 31 MB down to 20 MB. A 35% save!

The best bit?
UPX is usable on any other application you have. As long as they have *.exe and DLLs, you can use UPX on it.

5 thoughts on “Make your Firefox load faster!


  1. Wouldn’t compressing the ddls and exe require firefox to uncompress them at start-up or during runtime?
    If that’s the case then it sounds to me as it isn’t really worth the 11 mb gain.


    1. I haven’t really thought of that. But let’s say it’s during runtime, then no, it doesn’t matter, I suppose. Because then Firefox still has 11mb less to load, thus loading faster.

      But if it were to uncompress while starting up, then yes, the whole procedure would be moot. I guess, I’d have to check up on that.


      1. Yes, Firefox does have to decompress. However, on today’s processors, decompression is significantly quicker than spooling the extra data from the HDD (which haven’t changed that much in years).

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