Picking the Right 3D File Format
Every 3D format was designed for a different job. Choosing the wrong one means extra conversion steps, lost materials, or bloated files that tank performance. Here is a practical breakdown by use case.
Web and Real-Time Rendering
GLB is the standard for web delivery. It packages geometry, PBR
materials, textures, and animations into a single binary file. Add Draco compression
and a 50 MB model drops to 5 MB without visible quality loss. Every major browser,
three.js, Babylon.js, and Google's <model-viewer> component
support GLB natively. If your file will be displayed on a website, start here.
glTF (the JSON version) is useful during development because you can inspect the scene graph in a text editor. For production delivery, pack it into GLB so users download one file instead of a folder of loose assets.
AR Experiences
iOS AR Quick Look requires USDZ. There is no alternative. If your audience uses iPhones or iPads and you want that "tap to place" experience in Safari, you need a USDZ file. Android AR (Scene Viewer) takes GLB directly. Many teams produce both: GLB for web and Android, USDZ for iOS.
3D Printing and Manufacturing
STL is the default for desktop FDM printers and most slicers (Cura, PrusaSlicer, Bambu Studio). It stores raw triangle geometry with no materials or colors. That is exactly what slicers want.
3MF is the modern replacement. It supports colors, multiple objects, print settings, and thumbnails in a single ZIP-based package. Most new slicers accept 3MF, and some (like Bambu Studio) prefer it. If your slicer supports 3MF, use it over STL.
Game Engines (Unity, Unreal, Godot)
FBX has been the go-to interchange format for game engines for over a decade. Unity and Unreal have deep FBX import pipelines that handle skeletal animation, blend shapes, and material slots reliably.
GLB/glTF support in game engines is improving fast. Unity 2023+ and Unreal 5 both import glTF. For new projects, glTF's open specification and standardized PBR materials may be the better long-term bet. For legacy pipelines or teams with established FBX workflows, stick with FBX.
CAD and Engineering Exchange
STP (STEP) is the ISO standard for exchanging solid model data between CAD systems. If you receive a STEP file from a mechanical engineer or manufacturer, convert it to GLB for web viewing or STL for printing. STEP preserves precise NURBS surfaces, but most real-time renderers need triangle meshes, which is what the conversion produces.
Legacy and Universal Compatibility
OBJ has been around since the 1980s and opens in practically any 3D tool ever built. If you need to hand a file to someone and have no idea what software they use, OBJ is the safest bet. The tradeoff: no animation, no PBR materials, and larger file sizes compared to binary formats.
DAE (COLLADA) was designed as a universal interchange format and supports materials, animation, and scene hierarchy. In practice, it has been largely replaced by glTF for web and FBX for game engines, but some older tools and simulation software still expect it.