Compactster
Free up space on Windows. Your games and apps still open as usual.
Compactster compresses games, apps and folders so they take less room on your drive. It checks every file before and after, and any job can be undone.
Coming soon for Windows 10 and 11. Mac and Linux later.
Six real games, compressed
3,591 files7.26 GB4.27 GB
Measured on real files, not promised
Windows already includes a compression tool, compact.exe. Compactster uses the same compression built into Windows, but works through your files in parallel and still checks every one.
Six games, Balanced
7.26 GB, 3,591 files. Median of three rounds.
About 1.7× faster
One game, Strongest
A 5 GB game folder. Two rounds each.
About 1.7× faster
A folder of small files
62,569 files of a code project. Two rounds each.
About 1.4× faster
Copies of real games and folders on an NVMe SSD under Windows 11, measured in November 2026, alternating the two tools in the same session. The same Windows algorithm was used for both. compact.exe does not check files afterwards; Compactster checks every one. By default Compactster also skips files that would shrink by less than 5%, so it freed slightly less: 2.99 GB against 3.01 GB. Another tool that skips the check was about 20% quicker than Compactster on the six-game set. How much space you get back depends on the files: photos, videos and many newer games are already compressed and won't shrink much, and Compactster estimates that before it starts.
It won't touch what keeps Windows running
Compactster refuses system places outright, before it measures anything. In testing, it turned down all 15 places it should, each in under a tenth of a second.
Your original stays until the new one is checked
Nothing is replaced until the new version is complete and checked. If the PC crashes or loses power, Compactster picks up safely from its log when it starts again.
Every job can be undone
Compressed folders and games go back with one click. Converted photos and videos keep a private backup of the original for the days you choose. The Vault restores from its archive.
Games are handled with care
Games whose publishers ask not to be compressed are left alone. Games that are updating wait until the update ends, and automatic jobs wait while you play.
- The whole C: drive
- Windows
- System32
- WinSxS
- WindowsApps
- ProgramData
- Recycle Bin
- System Volume Information
- Page file
- Recovery
- Your user registry
- OneDrive
- Xbox games
- Antivirus folders
- Its own backups
Each was tried on purpose on a real Windows 11 PC. Each was refused.
Two ways to make room
Drop files, folders or games in the window. Compactster measures them first and estimates what you'll get back.
Compress
Smaller, and it opens as usual.
- Games, apps and folders shrink in place. Windows unpacks them as they're read.
- Photos, videos and documents can be saved in smaller formats.
- Finds your Steam, Epic and GOG games for you. Xbox and Microsoft Store games are protected by Windows, so they're left alone.
Vault
Packed away until you need it.
- Old projects and finished games go into one tightly packed archive.
- The archive is checked in full before the originals are removed.
- Restore everything or one file, or look inside without restoring.
The app after a job, shown with sample files.
Quiet when it's not working
0.2–0.4% of one core
That's the small background helper while idle, measured over minutes on a real PC. It uses about 25 MB of memory.
Pauses for your games
Automatic jobs wait while a game is running, and can wait for idle time or mains power too.
Close the window anytime
Jobs keep going in the background, and the tray icon shows when one is running.
Free for everything you do yourself
Pro is for when you want Compactster to keep your drives tidy on its own.
Free
Every job you start by hand.
- Compress, Vault, restore and undo
- Every safety check, always
- One watched folder
Pro
Compactster does it for you.
- Watch as many folders as you like, on a schedule
- Compress games again after they update
- Free space when a drive runs low
Free is for personal use. Pro comes with a 14-day free trial. Safety, undo and restore are never paid features. If Pro ends, automatic jobs pause and nothing already compressed or packed is changed.
Questions
Is it safe for my files?
The original is never changed until the new version is complete and checked. Every file is read before and after compression. Every job can be undone, and system folders are refused outright.
Will my games run slower?
Compressed files are unpacked as they're read. In our tests they took longer to read on fast SSDs, and more so with the Strongest setting. If a game feels slower, uncompress it with one click.
How much space will I get back?
It depends on the files. The six games in our test went from 7.26 GB to 4.27 GB, 41% less. Photos, videos and games that are already compressed shrink very little. Compactster measures first and tells you before it changes anything.
What happens when a game updates?
Compactster waits until the update is finished. New and changed files arrive uncompressed. With Pro, Compactster compresses them again automatically.
Which computers will it run on?
Windows 10 and 11 first. Mac and Linux versions are on the way. On Windows, compressing in place needs an NTFS drive, which most Windows drives are. On other drives, Compactster tells you and offers the Vault instead.
Want to know when it's out?
Send one email and we'll write back when Compactster is ready to download.