There are over 40 different texture compression formats available in Unity 2021, and each has been designed to support a particular set of use cases. With so many options, picking the right one for you can sometimes feel overwhelming.
This quick-reference cheat sheet contains every single texture compression format available in Unity 2021, and will allow you to compare and contrast them to find the right compression settings for your project.
This page is intended to be used as a companion to Your Guide to Texture Compression in Unity, an article which explores the principles of texture compression in greater depth and provides recommendations for a range of common applications.
This information was gathered from an installation of Unity 2021.1.7f1.
Color/Bit depth
| Depth | Colors |
|---|---|
| 8-bit RGB | 256 |
| 16-bit RGBA | 256 + alpha |
| 16-bit RGB | 65,536 |
| 24-bit RGBA | 65,536 + alpha |
| 24-bit RGB | 16,777,216 |
| 32-bit RGB | 16,777,216 + alpha |
Uncompressed formats
| Format | Color Depth | Distribution | sRGB support |
|---|---|---|---|
| R 8 | 8 | R8 | No |
| Alpha 8 | 8 | A8 | No |
| R 16 bit | 16 | R16 | No |
| RGBA 16 bit | 16 | R3 G3 B2 A8 | No |
| RGB 16 bit | 16 | R5 G6 B5 | No |
| RGB 24 bit | 24 | R8 G8 B8 | Yes |
| RGBA 32 bit | 32 | R8 G8 B8 A8 | Yes |
| RGB 48 bit | 48 | R16 G16 B16 | No |
| RG 32 bit | 32 | R16 G16 | Yes |
| RGB9e5 32 bit Shared Exponent Float | 32 | * | No |
| RGBA Half | 64 | R16 G16 B16 A16 | No |
* RGB9e5 is a little more complicated than a straightforward division of bits into a series of color channels. For more information, check out the Unity Documentation on the format here.
Compressed formats
| Format | Channels | Bits per pixel | sRGB support | Compression ratio* |
|---|---|---|---|---|
| DXT1|BC1 | RGB | 4 | Yes | 6:1 |
| DXT5|BC3 | RGBA | 8 | Yes | 4:1 |
| BC4 | R | 4 | No | 2:1 |
| BC5 | RG | 8 | No | 2:1 |
| HDR BC6H | RGB | 8 | No | 4:1 |
| BC7 | RGB/A | 8 | Yes | 4:1 |
| ETC 4 bits | RGB | 4 | Yes | 6:1 |
| ETC2 8 bits | RGBA | 8 | Yes | 4:1 |
| ETC2 4 bits | RGB | 4 | Yes | 6:1 |
| RGB + 1-bit Alpha ETC2 4 bits | RGBA* | 4 | Yes | 6:1 |
| EAC 4 bit | R | 4 | No | 2:1 |
| EAC 8 bit | RG | 8 | No | 2:1 |
| PVRTC 4 bits | RGBA | 4 | Yes | 8:1 |
| PVRTC 2 bits | RGBA | 2 | Yes | 16:1 |
| ASTC 12×12 block | RGBA | 0.89 | Yes | 36:1 app. |
| ASTC 10×10 block | RGBA | 1.28 | Yes | 25:1 app. |
| ASTC 8×8 block | RGBA | 2 | Yes | 16:1 |
| ASTC 6×6 block | RGBA | 3.56 | Yes | 9:1 app. |
| ASTC 5×5 block | RGBA | 5.12 | Yes | 7:1 app. |
| ASTC 4×4 block | RGBA | 8 | Yes | 4:1 |
| ASTC HDR 12×12 block | RGBA | 0.89 | No | 36:1 app. |
| ASTC HDR 10×10 block | RGBA | 1.28 | No | 25:1 app. |
| ASTC HDR 8×8 block | RGBA | 2 | No | 16:1 |
| ASTC HDR 6×6 block | RGBA | 3.56 | No | 9:1 app. |
| ASTC HDR 5×5 block | RGBA | 5.12 | No | 7:1 app. |
| ASTC HDR 4×4 block | RGBA | 8 | No | 4:1 |
* Depending on the number of channels in the compression format, ratios were calculated by the comparison to an uncompressed R8, RGB 24-bit, or RGBA 32-bit texture.
** As its name suggests, the RGB+ 1-bit Alpha format uses a 1-bit alpha channel.
Further reading
Thanks for checking out my breakdown of the compression formats available in Unity 2021. I hope you found what you were looking for!
The art of texture compression (and more broadly speaking, graphics programming as a whole) is a wonderful rabbit hole of which I’ve only just scratched the surface. The information on this page reflects my best attempt to simplify sometimes very complex systems to provide practical answers to your questions.
If you’d like to explore this world further, the Unity Documentation has a wealth of additional information which should point you in the right direction.
Good luck!
