Free online GLB to X converter

Conversion is needed when a legacy DirectX application, game engine, or modeling tool accepts only the Microsoft X mesh format. It also provides a text or binary asset for older Windows 3D pipelines, but materials, animation, and coordinate conventions may need correction.

What the GLB format is

GLB is the usually single-file, binary form of glTF 2.0. It can contain mesh geometry, vertex data, PBR materials, embedded textures, skinning, morph targets, cameras, and animations. Web 3D viewers, game engines, AR applications, and tools such as Blender, 3ds Max, Maya, Godot, and Unity commonly use it for asset delivery and interchange.

Unlike a separate .gltf file with external buffers and images, a GLB normally packages the glTF JSON description, binary mesh data, and referenced textures in one container. Packaging does not guarantee that every resource is embedded, so verify the file if an importer reports missing images.

What the X format is

DirectX X is a legacy Microsoft 3D scene format used by older DirectX SDK samples, Windows applications, and game engines. It can describe polygon meshes, normals, texture coordinates, materials, scene frames, bones, and animation data.

X files can be text or binary. Text files are inspectable and sometimes easier to modify; binary files are smaller and require an importer that supports the binary variant. X is useful mainly for compatibility with software that specifically requires it, because its material model does not represent modern glTF PBR data completely.

How to convert GLB to X

For a conversion without installing desktop software, use the converter on 101convert.com: upload the .glb file, select X as the output format, start the conversion, and download the resulting .x file. Select text or binary X when the destination program requires a particular variant, if that option is available.

For local or batch processing, Assimp provides a command-line workflow:

1. Install an Assimp package that includes the command-line executable and its X exporter.
2. Inspect the source with assimp info model.glb to check meshes, materials, bones, and animations.
3. Export it with assimp export model.glb model.x. The .x output extension selects the DirectX X exporter.
4. Open the result in the target application and test scale, orientation, textures, skinning, and animation playback.

Assimp builds and exporters vary by package, so confirm that the installed build lists X support before relying on a batch workflow. If it cannot produce the structure required by the destination, import the GLB into Blender and use an X-format exporter add-on compatible with the installed Blender version. Blender does not provide a standard built-in DirectX X exporter in its normal installation; the add-on supplies the export command under File → Export.

Quality and compatibility limits

GLB metallic-roughness PBR materials do not map directly to the older X material model. Diffuse color, a basic image texture, and some specular settings usually transfer; metallic, roughness, clearcoat, transmission, detailed emissive effects, and texture transforms may be simplified or discarded. Keep the original GLB and source textures if the converted file must be revised later.

glTF uses a right-handed coordinate system with Y up. The X file format does not enforce one universal application coordinate convention, and many DirectX pipelines use a left-handed system. Check the destination application's requirements before applying an axis conversion, rotation, or triangle-winding reversal; an automatic correction can otherwise make the model face backward or render inside out.

Test animated assets separately. Exporters and importers may disagree about bone hierarchies, bind poses, frame transforms, animation clips, and morph targets. If animation fails, export a static mesh first, then test skinning and animation with a smaller asset. Also confirm that the destination can find external texture files, because an X exporter may write references rather than embed images.