FBX 3D models are often large because the format embeds multiple data types—like high-poly meshes, uncompressed textures, animations, rigs, and materials—in one file, preserving full asset details but increasing size.
- **All-in-one design**: FBX packs every component of an asset into a single file (instead of linking external files), which is convenient but adds bulk. - **Uncompressed quality**: To maintain functionality (e.g., rigged characters for animation), FBX retains uncompressed data by default, boosting size.
To reduce FBX size, export only essential elements: lower polygon counts, use compressed textures, or link external assets instead of embedding them.