A Guide to Texture Optimization for glTF Files

Choose KTX2, WebP, or core image formats with explicit tradeoffs for transfer size, visual detail, runtime support, and tooling compatibility.

Textures can account for a large share of a glTF or GLB asset. Inspect the asset first, then choose image formats, dimensions, and quality settings based on measured size and the target runtime.

KTX2 and Basis Universal

KTX2 with Basis Universal can reduce transfer size and transcode to GPU-supported texture formats at runtime. Use it when the target engine and deployment include the required loader and transcoder, and compare artifacts and GPU memory on representative devices.

When to use WebP

WebP is useful for browser-focused delivery and quick iterations. It changes the glTF extension requirements and lossy settings can affect edges, text, normal maps, and alpha, so verify the actual target viewers.

Quality settings that matter

  • Test several quality values on representative color textures.
  • Inspect normal maps and packed data textures separately.
  • Downscale only after checking the largest on-screen use.

For a complete end-to-end compression workflow, see the staged GLB compression workflow, and compare tools on the GLB tool comparison.