"Windows protected your PC"
SmartScreen shows this for programs it hasn't seen much of, with the publisher as Unknown. Press More info, then Run anyway.
Free for Windows 10 or 11
Download Karoball
Karoball comes as a small launcher. Unzip it, run it, and it downloads the game for you.
The button opens Karoball's page on itch.io, where the download is.
On an Android phone? Karoball for Android is in closed testing on Google Play, and anyone can join. How to join the test. There's no Mac or Linux version; see other platforms.
<5 MBLauncher zip
28 MBGame, on first start
~0.5 MBA usual update
FreeNo ads, no paid extras
Five steps
Install
There's no installer and nothing to set up. Karoball needs no admin rights and writes nothing next to the exe, so the folder can live anywhere.
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Get the zip
Press Download on itch.io. On Karoball's itch.io page, press Download next to Karoball for Windows and save the zip (under 5 MB).
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Unzip it
Right-click the zip and choose Extract All, then pick a folder. Your Desktop is fine. Don't run the game from inside the zip: it needs the files that sit next to it.
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Run Karoball.exe
Open the
Karoballfolder and double-clickKaroball.exe. If Windows says Windows protected your PC, press More info, then Run anyway. Why it asks. -
Let it download the game
The first start downloads the game (28 MB) with a progress bar, then starts it in the same window. After that, each start only checks for updates.
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Make an account and play
Press Play, then Register on the Log In card. Pick a username and a password of at least 3 characters. You don't need an email address. Log in, and you're on the play menu.
Use a password you don't use anywhere else. The game remembers your login on this PC.
New to it? How to play walks you through your first match.
Windows warnings
If Windows or your antivirus warns you
Karoball is new and its launcher isn't code-signed, so Windows SmartScreen and some antivirus programs don't know it yet and may warn about it. It's a false positive.
Smart App Control blocked it
Windows 11's Smart App Control, if it's turned on, can block new programs that aren't code-signed, with no Run anyway button. If that happens to you, ask on Discord.
Your antivirus removed a file
If it quarantined Karoball.exe or https.dll, the launcher won't start or says https.dll is missing. Restore the file from quarantine and allow the Karoball folder, or extract the zip again.
Optional: unblock the zip first
Before you extract it, right-click the zip, choose Properties, tick Unblock and press OK. That removes the "downloaded from the internet" mark, so SmartScreen won't ask.
What the launcher does
- It downloads the game over HTTPS from Karoball's download server, or from a mirror if that one is blocked.
- It checks every file before running it. The list of game files carries the developer's signature, and each file has to match its published SHA-256. A broken or tampered download is never run.
- It installs nothing else. It needs no admin rights, starts no other programs and writes nothing outside its own folders.
- It sends nothing about you, it only downloads files.
That signature check covers the game files the launcher downloads. Karoball.exe itself is not code-signed, which is why Windows asks.
The file
What you download
- File
- Karoball for Windows on itch.io, a zip of the launcher
- Size
- Under 5 MB zipped, about 9 MB unzipped
- Inside
- A
Karoballfolder:Karoball.exe, the files it runs on and their licences - Game version
- 0.1.42, released 1 November 2026 · what's new
- First start
- Downloads the game: 28 MB
- Platform
- Windows 10 or 11
- Price
- Free. No ads and no real-money purchases
No need to check anything by hand: the launcher checks every game file it downloads against its published SHA-256 and won't run one that doesn't match.
System requirements
What you need
Karoball is a small game, and this is all it needs.
- System Windows 10 or 11
- Controls Keyboard and mouse No controller support
- Graphics A graphics card or chip with OpenGL 2.1
- Disk About 30 MB Plus your saves and screenshots
- Internet Online only Bots and challenges run on the server too
- Language English
Launcher says "The launcher is missing https.dll"? Your PC needs Microsoft's Visual C++ 2015-2022 Redistributable, the x86 one (even on 64-bit Windows). Install it, then start Karoball again.
Updates
Updates install themselves
You only download the zip once. Every time you start Karoball, the launcher checks for a new version and fetches only what changed.
- 1Checking for updates
- 2Updating to 0.1.42
- 3Starting Karoball 0.1.42
- Most updates are about half a megabyte. The odd one that changes the art is bigger, up to about 18 MB.
- After a brief break in the connection, the download carries on from where it stopped.
- There are two download hosts, and if one is down or blocked the launcher uses the other.
- The launcher updates itself too.
"Update needed"
If a new version comes out while the game is open, it may say Update needed. Press Restart and the launcher fetches it.
See what changedUninstall
Removing Karoball
There's no uninstaller because there's nothing installed. Delete these three folders. Type %APPDATA% into File Explorer's address bar to find the last two.
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The
Karoballfolder you unzippedKaroball.exeand the files next to it. -
%APPDATA%\Karoball LauncherThe downloaded game files, about 20 MB.
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%APPDATA%\KaroballSettings, your saved login, replays, screenshots and crash reports. Copy
Screenshotsandreplaysout first if you want to keep them.
Your account and progress live on the server, so deleting these loses nothing but local settings and files. Download it again any time and log in.
Other platforms
Windows now, Android in testing
Karoball runs on Windows, and the Android version is in closed testing on Google Play. Here's where everything else stands.
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Windows
Available
Windows 10 or 11, free.
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Android
Closed test
Free, with the same account and progress as on Windows. Anyone can join the test, on the Google account the phone uses:
More about the test. The old 2022 and 2023 Android apps can't join today's server; uninstall them first.
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Steam
Not yet
Nothing on Steam yet.
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Mac and Linux
No version
There's no Mac or Linux version of Karoball.
Join the Discord to hear first when that changes.
Troubleshooting
If something goes wrong
The most common problems, by what you see on screen.
"The launcher is missing https.dll"
Reinstalling won't fix this one. Install Microsoft's Visual C++ 2015-2022 Redistributable (x86) and start Karoball again. If it still says so, check your antivirus hasn't quarantined https.dll: restore it, or extract the zip again.
"Couldn't download Karoball" or "Couldn't download the update"
The launcher couldn't reach either download host, or the download kept breaking off. Check you're online and press Retry. On a school or work network the downloads may be blocked (see below).
"Update needed"
A new version came out while the game was open. Press Restart: the launcher downloads it and starts the game again.
"Server is Currently Offline"
The game server is down or restarting. Check the Discord for news, then try again.
The game runs slowly
In Settings › Graphics, turn off Lighting and Day and Night, set Anti Aliasing to 0, and try Windowed or Limit FPS.
It won't connect on a school or work network
The game needs outgoing UDP on ports 3000 and 3001 to eu1.karoball.net, and the launcher needs HTTPS to dl.karoball.net and f005.backblazeb2.com. Some networks block these. Ask whoever runs the network, or play from home.
"Couldn't save the update"
Free up some space. An update that changes the art needs about 20 MB free on top of the game, because the new files are saved before the old ones are deleted.
The game crashed
The crash screen saves a report and has a Copy report button. Paste it to us on the Discord: it helps get the bug fixed. Reports are also kept in %APPDATA%\Karoball\crashes.
If you were in a match, start the game again: Play shows Your match is still on with a Rejoin button while your place is kept.
More answers about accounts, servers and playing in the FAQ.
Stuck? Ask on Discord
Help, bug reports and server news all go through the Karoball Discord, which has 245 members. You can also email support@karoball.net.