STL vs. OBJ vs. GLB: Choosing the Right 3D File Format

Does the File Format Really Matter?

You've just generated an amazing 3D model from your photo. Now it's time to download it, but you're faced with a choice: STL, OBJ, or GLB? While they all represent 3D objects, they are designed for very different purposes. Choosing the right one is crucial for getting the best result in your 3D printer, game engine, or web viewer. Let's break it down.

STL (Stereolithography): The King of 3D Printing

If your goal is 3D printing, STL is almost always your answer. It's the simplest and most universal format for this purpose.

• What it stores: Only the surface geometry of the object—a collection of interconnected triangles (a "mesh").
• What it doesn't store: Color, texture, material, or lighting information.
• Pros: Simple, lightweight, and supported by every single 3D slicer software (like Cura, PrusaSlicer, etc.).
• Cons: Useless for anything requiring color or visual appearance, like a game asset or AR object.

OBJ (Object File): The Versatile Veteran

OBJ is an older but still incredibly popular and versatile format, widely supported by 3D modeling software and game engines.

• What it stores: Geometry (the mesh), UV mapping coordinates (how textures wrap around the model), and material information.
• How it works: The material and texture information is often stored in a separate companion file with a .mtl (Material Template Library) extension, which must be kept with the .obj file.
• Pros: Widely supported, good for transferring models between different 3D software.
• Cons: Managing multiple files (OBJ, MTL, and texture images) can be cumbersome.

GLB / glTF: The Modern Standard for Web and AR

Think of GLB as the "JPEG of 3D." It's a modern, efficient format designed to be a compact, all-in-one package for sharing and displaying 3D models on the web, in AR/VR applications, and in real-time engines.

• What it stores: Everything in one file! Geometry, materials, textures, and even animations. The 'B' in GLB stands for binary, meaning all this data is packed into a single, efficient file. (glTF is the JSON-based version, but GLB is more common).
• Pros: All-in-one file is easy to share and use. Highly optimized for real-time rendering on web and mobile. The official format for Facebook 3D posts.
• Cons: While some slicers are starting to support it, it's not as universally accepted for 3D printing as STL.