texture-compression-astc

ASTC compresses textures in variable block sizes (4×4 up to 12×12), letting artists trade quality against size per texture. WebGPU exposes its LDR formats with linear and sRGB variants; the feature does not expose ASTC HDR formats. The choice of block size makes it a flexible alternative to ETC2 and BC.

It is the native choice on recent ARM and Qualcomm mobile GPUs and on Apple silicon. Desktop NVIDIA/AMD/Intel hardware largely does not decode ASTC in silicon, so availability closely tracks the mobile/Apple share of the sample.

The sliced-3D variant additionally allows 3D textures with per-slice ASTC compression.