A fan-made widescreen remaster of Sonic 3 & Knuckles.
Before downloading, please make sure you have the Steam version of
Sonic 3 & Knuckles 
installed on your PC.
Summer Update 2022 - v22.09.10.0
Recommended download.
Includes the actual game, as well as the open source game scripts.
Download ZIP via Github
View Changelog
Current Preview Version - v22.08.27.0
Slightly more experimental.
Note that the preview version is just an intermediate build or a candidate for a proper update.
It is not well tested yet and possibly contains new bugs.
Before downloading, please make sure you have the Steam version of
Sonic 3 & Knuckles
installed on your PC.
Summer Update 2022 - v22.09.10.0
Recommended download.
Includes the actual game, as well as the open source game scripts.
Download TAR.GZ via Github
View Changelog
Current Preview Version - v22.08.27.0
Slightly more experimental.
Note that the preview version is just an intermediate build or a candidate for a proper update.
It is not well tested yet and possibly contains new bugs.
The macOS port by Sappharad.
Before downloading, please make sure you have the Steam version of
Sonic 3 & Knuckles
installed on your Mac.
.
The Beta version for Android.
Before downloading, please make sure you have the Steam version of
Sonic 3 & Knuckles
installed on your PC or Mac.
You will need to transfer the Sonic 3 & Knuckles Steam ROM file from there to your Android device.
.
The Beta version for iOS and Web by Sappharad.
Before downloading, please make sure you have the Steam version of
Sonic 3 & Knuckles
installed on your PC or Mac.
This is required for iOS as well - you will need to transfer the Sonic 3 & Knuckles Steam ROM file from there to your iOS device.
.
The Switch Homebrew Port by heyjoeway.
You need a modded Switch, and also the Steam version of
Sonic 3 & Knuckles on your PC or Mac.
.
Join the official Sonic 3 A.I.R. Community Discord Server !
For news on the project, follow me @Eukaryot3K on Twitter .
Sonic 3 A.I.R. is Open Source! Check out the whole project on Github .
There's a Manual PDF to check out!
You can find useful information on various topics in there, including troubleshooting problems as well as explanations for the in-game options.
(Yes, this is the same as the one included in all game installations.)
There's some questions I get asked practically every single day. So here's some answers.
How do I install Sonic 3 A.I.R.? (Windows)
Just download one of the ZIP files for either the stable or preview versions, and extract it to some location on your hard drive (e.g. on your desktop, or your documents folder, etc.). Now you can start the Sonic3AIR.exe there. That's all.
How do I update to a new version of Sonic 3 A.I.R.? (Windows)
It's as easy as installing the new version, preferrably to a different location than the old installation. Your existing save game data will be used by the new version as well, as it's stored outside of the actual game installation (see the game's Manual PDF for details).
After a quick check if the new version is working, you can safely delete the old game installation.
How do I install / update Sonic 3 A.I.R.? (Other platforms)
Have a look at the Manual PDF , you can find all information there.
What to do when there's graphics issues with Sonic 3 A.I.R.?
Changing the renderer to OpenGL Software could help. If not, try switching to fail-safe mode. For instructions on that, have a look at the Manual PDF linked above.
What to do when the game just crashes on startup?
A common problem is graphics driver issues. You should definitely make sure your graphics drivers are up-to-date. If you're at the latest drivers already, you can still switch the game to fail-safe mode, as described in the Manual PDF linked above.
Why can't I just use any Sonic 3 & Knuckles ROM?
Getting the Steam version of Sonic 3 & Knuckles and using its ROM is a clean, 100% legal way to get S3AIR running. Using just any ROM downloaded from somewhere on the internet is not. This project does not endorse piracy in any way.
Aside from that, there's also a hard technical requirement to use that exact ROM: S3AIR loads a lot of data directly from the ROM and expects all of that in very specific locations. Other ROMs than the Steam versions usually don't use the exact same internal layout, so reading anything from those would only produce garbage data that the game can't handle, so it would probably crash right away.
That's also why you can't just plug in a S3&K ROM hack and expect that to work with S3AIR.
The Steam ROM is not available for purchase any more, what now?
Unfortunately, there's no easy answer to that. You might be lucky and already have Sonic 3 & Knuckles in the SEGA Mega Drive & Genesis Classics on Steam. If not, check out these legal alternatives .