Optimizing VRM models
Inspect VRM texture references, use Prune carefully and verify expressions and compatibility after optimization.
Inspect references before removing textures
A VRM texture can be referenced by VRM material properties or model metadata even when it is not used by a standard glTF material slot. The thumbnail is one example. Check the texture’s Used by details: absence from the visible model does not necessarily mean it is unused. Prune removes unreferenced data, not every texture that is invisible in the current preview.
Evaluate one optimization at a time
Begin with all options off, then enable Prune, texture resizing, KTX2 or Simplify as needed. Exclude sensitive geometry from Simplify and inspect faces, hair, outlines and transparent materials. KTX2 and Meshopt support depends on the destination application. Preserving extension data does not by itself guarantee compatibility with every VRM viewer.
Compare, download and test the result
Each conversion starts from the model originally loaded into the workspace, not the previous result. Review the size and geometry statistics, then use the comparison slider to check appearance. Download explicitly when satisfied. Test expressions, skeleton movement and materials in the application where the avatar will be used, and keep the original file. Browser reload protection is a warning, not a backup of the model or settings.