CompactGUI: Compress your Games & Applicatons to gain some SSD space

CompactGUI is a must have tool for Windows and Gamers, that is for sure but it also can help the normal user to compress larger applications, the benefit is that you save a lot of storage and the application might load faster.

Final Fantasy from 23 to under 1.2 GB compressed!


The program is free and open source, it’s available on GitHub.


The GUI doesn’t offer much, you select the folder and that’s it, the entire magic is handled via a triggered command line parameter.

CompactGUI Options

How does it work?

Basically it works with the Windows own compact option, an explanation is given here. You also could compact your entire OS, but from my experience there is not really a benefit, maybe the SSD footprint but it also can create problems with some applications, so I suggest you start first with CompactGUI.


  • SSD space is not cheap, so go ahead and save some space.
  • Faster loading speed because the application is faster to load due the efficient compressing algorithm.

What kind of gains can you expect from compacting folders and files within? This depends largely on the type of files – the developer compressed the Adobe Photoshop folder and cut its size in half by doing so and I was able to compress a recent Final Fantasy Version to under 1.2 GB, that’s insane!

Final Words

Do you noticed that I not talked about the cons? Because there are no cons and the program works at least for me perfect, of course it’s always possible that a game isn’t compatible but it shouldn’t be a big deal to do a backup or to re-install the game. Does it work with Steam and Origin Games too? Sure, it doesn’t trigger any anti-cheat mechanism because it’s only a compression and not any special voodoo.

Go ahead, show me your results.


Windows reports the compressed file size using only a 32-bit unsigned integer, so whenever the end-result of compressing a single file is larger than 4GB (2^32 bytes = 4GB), the result wraps around and starts at 0 again. So when the compressed file ends up being 4.5GB big, it instead displays incorrectly as being only 0.5GB big (4.5GB – 4GB = 0.5GB).

What does it mean?

The developer needs to change the program to display the correct values, you still can get a solid compression but not over 100% or such ridiculous values, points out that I could save 9% on Final Fantasy. This is why FF XII seemed to compress from 29GB to just 1GB. The math here is 29GB – 4GB*7 = 1GB. However, the program is still not bad!