Simplify and encode GLTF geometry, download optimized GLB.
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Accepts .gltf (with .bin and textures). Applies mesh simplification and Meshopt (recommended) or Draco. Outputs an optimized GLB. Textures unchanged. Fully local.
Default50%
Range0% – 100% · step 5%
Reduces the number of faces and vertices using mesh simplification. Default medium strength; increasing strength shrinks file size further but may lose surface detail. Only affects geometric density, not the container format.
DefaultOn
Applies EXT_meshopt_compression to glTF/GLB, compressing geometry buffers without changing face count. Enabled by default for runtime-friendly loading. Mutually exclusive with Draco. Not used for non-glTF outputs like STL, OBJ, or FBX.
Default. Enables Meshopt container compression.
Do not write Meshopt extension.
DefaultHigh
Controls Meshopt encoding strategy. Default 'High' generally yields smaller size and enables attribute filters, suitable for most web scenarios. 'Medium' applies more uniform quantization across attributes, which may be preferred by conservative toolchains.
Default. More aggressive compression with filters, usually smaller.
More uniform quantization; compression ratio is usually slightly lower.
DefaultOff
Applies KHR_draco_mesh_compression to glTF/GLB. Often yields smaller files than Meshopt but with higher decoding overhead. Disabled by default; mutually exclusive with Meshopt. Not used for non-glTF outputs.
Default. Do not write Draco extension.
Enable Draco (disables Meshopt).
Default6
Range1 – 10
Draco encode/decode speed trade-off, range 1, 10. Higher values favor smaller size at the cost of encode speed. Default 6 is suitable for most models.
DefaultEdgebreaker
Draco topology encoding method. Default Edgebreaker typically gives better compression for triangle meshes. Sequential can be more suitable for ordered strips or point sequences.
Default. Best for common triangle meshes.
Suitable for ordered strips and special topologies.
Shown under Advanced settings in the UI. Vertex attribute precision when Meshopt or Draco writes glTF. Defaults: position 14, normal 10, UV 12. Lower bits shrink files more but raise crack, shading, or UV artifact risk.
Default14
Range8 – 16
Quantization bits for POSITION attribute (8, 16). Default 14 balances file size and cracking risk. Too low may cause gaps or jitter.
Default10
Range8 – 16
Quantization bits for NORMAL attribute (8, 16). Default 10. Too low may cause shading artifacts.
Default12
Range8 – 16
Quantization bits for TEXCOORD attribute (8, 16). Default 12. Too low may cause texture crawling or jitter.
Drop .gltf plus referenced resources
Simplification + Meshopt or Draco
Download optimized GLB
Compressed glTF is delivered as a single optimized GLB for portability and engine support: one binary file with the encoded geometry embedded. GLB loads faster than a .gltf with external .bin and textures and is easier to host.
Meshopt is designed for fast decoding on the web and mobile, so it's the recommended default for loading performance. Draco often produces smaller files at the cost of more decode time. Only one can be enabled on the same geometry.
Yes. This tool only processes geometry buffers; textures are embedded in the output GLB exactly as they were in the source, with no quality loss.
Yes. Disable container encoding and the tool applies mesh simplification only; the output is still an optimized GLB with the reduced geometry. That's useful when you want fewer polygons without re-encoding buffers.
Draco is Google's open-source library for compressing 3D geometry and point clouds. It can shrink mesh buffers by up to 90% with little visible loss. Meshopt is the alternative, usually faster to decode, occasionally slightly larger.
Yes. Three.js loads GLB/GLTF natively and supports both Draco (via DRACOLoader) and Meshopt (via MeshoptDecoder). Include the matching decoder in your project. With Meshopt it ships in three's examples folder.
How many bytes does vertex data actually take? Quantization, MeshOpt, and Draco - which tool fits which scenario? It's not about 'Draco is best,' but 'the right tool for the right job.'
Take a 50MB PBR model through the full pipeline—Blender export, vertex compression, KTX2 texture conversion, engine loading—and get it under 5MB. Includes a complete automation script and a series cheat sheet.
Desktop, mobile, VR, mini-programs—which compression combination should you use? This article consolidates the knowledge from the previous four articles into a decision matrix and an automation script—just follow it.
ETC1S or UASTC? How to use toktx and gltf-transform? How to load KTX2 in Three.js / Babylon.js? This article is full of copy-paste-ready commands and code.
