GLB vs OBJ vs USDZ: Which 3D File Format Do You Need?

If you've ever generated a 3D model and been greeted by a dropdown of export formats, you know the feeling: GLB, OBJ, USDZ, STL... which one do you actually need? The answer depends entirely on what you're planning to do with your model, and picking the wrong format can mean extra conversion steps or lost texture data.

This guide breaks down the four most common 3D file formats, explains what each one is good at, and helps you choose the right one for your project. Whether you're 3D printing a figurine, previewing a model in AR on your phone, or importing into Blender for editing, there's a format that fits.

Quick Comparison Table

GLB (GL Binary / glTF)

GLB is the binary version of glTF 2.0, an open standard maintained by the Khronos Group (the same organization behind OpenGL and Vulkan). Think of glTF as the "JPEG of 3D" -- it was designed from the ground up to be efficient, portable, and easy for software to read.

A GLB file bundles everything into a single file: the 3D geometry, PBR (physically-based rendering) textures, materials, and even animations if the model has them. You don't need to worry about missing texture files or broken material links. Just one .glb file, and you're good.

Why GLB works so well

GLB's biggest strength is its universality. It works nearly everywhere:

• Web viewers: Three.js, Babylon.js, and model-viewer all support GLB natively
• Mobile: Both iOS and Android can render GLB files
• AR: Google's Scene Viewer on Android uses GLB for AR preview
• Game engines: Unity and Unreal Engine both import GLB/glTF
• Social platforms: Facebook, Sketchfab, and other platforms accept GLB uploads

The format also uses efficient binary packing, so file sizes stay small compared to OBJ or FBX. This matters when you're sharing models over the internet or loading them on mobile devices where bandwidth and storage are limited.

GLB in Image to 3D

When you convert a photo to a 3D model in Image to 3D, GLB is the default export format -- and for most people, it's the best choice. The exported GLB includes full PBR textures, so your model looks accurate and detailed whether you're viewing it in an AR app, uploading it to a web gallery, or importing it into a game engine.

If you're not sure which format to pick, go with GLB. It covers the widest range of use cases.

OBJ (Wavefront)

OBJ is one of the oldest 3D file formats still in active use. It was created by Wavefront Technologies back in the 1980s, and it's stuck around because it's dead simple. Nearly every 3D application on the planet can open an OBJ file.

Unlike GLB, OBJ doesn't bundle everything into one file. An OBJ export typically includes:

• The .obj file itself (geometry and vertex data)
• A .mtl file (material definitions)
• Separate image files for textures (PNG, JPG, etc.)

This multi-file structure is both OBJ's greatest strength and its biggest headache. On the plus side, you have direct access to each texture file, which makes it easy to swap textures, tweak materials, or reorganize assets in a professional pipeline. On the downside, if you lose or misplace the .mtl or texture files, your model shows up as a gray blob.

Where OBJ shines

OBJ is the format to use when your next step involves editing the model in professional 3D software:

• Blender (free and open source)
• Autodesk Maya
• Autodesk 3ds Max
• ZBrush for sculpting
• Cinema 4D

These tools all handle OBJ imports seamlessly. If you want to retopologize your model, adjust UVs, repaint textures, or combine it with other assets, OBJ gives you the most flexibility.

OBJ limitations

OBJ doesn't support animations, so if you ever plan to rig or animate a model, you'll eventually need to convert to a different format. File sizes also tend to be larger since textures aren't compressed the way they are in GLB. And managing multiple files means you need to keep everything in the same folder -- renaming or moving one file can break the whole thing.

OBJ in Image to 3D

Image to 3D exports as GLB, but if you need OBJ for a 3D editing workflow, you can convert in Blender in under a minute: import the GLB, then export as OBJ. This gives you the separate texture files that some professional tools prefer. Check out the features page for a full overview of the app's capabilities.

USDZ (Universal Scene Description)

USDZ is Apple's 3D file format, built on top of Pixar's USD (Universal Scene Description) framework. If you've ever tapped a 3D model link on an iPhone and seen it appear on your desk through your camera, that was USDZ and Apple's AR Quick Look working together.

The format packages geometry, textures, materials, and animations into a single compressed archive (it's technically a zip file with a specific structure). Apple designed it specifically for AR experiences on their platforms, and it shows -- everything just works.

What makes USDZ special

USDZ has one killer feature that no other format matches: native AR support across the entire Apple ecosystem.

• Safari: Tap a USDZ link and the model opens directly in AR Quick Look
• Messages and Mail: Send a USDZ file and the recipient can preview it in AR right from the conversation
• Files app: Browse and preview 3D models with a tap
• Reality Composer: Build AR scenes using USDZ assets

For anyone with an iPhone or iPad, USDZ provides the most frictionless way to see a 3D model placed in your actual environment. Want to see how a 3D model of your pet would look sitting on your bookshelf? USDZ and AR Quick Look make that possible with zero extra apps.

USDZ limitations

The main drawback is ecosystem lock-in. USDZ works beautifully on Apple devices, but support on Android and Windows is limited. Some 3D tools like Blender can import USDZ, but it's not as universally supported as GLB or OBJ for editing workflows. If you need cross-platform compatibility, GLB is a better choice.

USDZ in Image to 3D

Image to 3D exports as GLB, which you can share directly from the app. If you need a USDZ file for AR Quick Look on iOS, you can convert the GLB in Blender or Apple's Reality Converter (free). It's especially fun for models you plan to 3D print later, since you can get a sense of size and placement before committing to a print.

STL (Stereolithography)

STL has been the standard 3D printing format since the 1980s when Chuck Hull invented stereolithography (the first commercial 3D printing technology). It's the format that every slicer program expects, and every 3D printer can work with.

But here's the thing about STL: it only stores geometry. No colors, no textures, no materials -- just the shape of the model defined as a mesh of triangles. This makes it perfect for 3D printing, where the printer only needs to know the physical form, but useless for anything where visual appearance matters.

STL strengths

For 3D printing workflows, STL is hard to beat:

• Universal slicer support: Cura, PrusaSlicer, OrcaSlicer, Bambu Studio -- they all work with STL
• Simple and predictable: What you see in your slicer is what you'll get on the printer
• Widely supported: Every 3D printer manufacturer supports STL
• Small learning curve: No texture or material complexity to worry about

STL weaknesses

The lack of color and texture data is a significant limitation. If you're working with a model that was generated from a photo, the beautiful textures that make it look realistic won't carry over to STL. You'll get the shape, but not the appearance.

STL files can also be surprisingly large for complex models because the format stores raw triangle data without any compression.

STL and Image to 3D

Image to 3D exports as GLB. If you need an STL file for your 3D printer, converting is straightforward.

How to convert to STL using Blender (free):

1. Export your model from Image to 3D as GLB
2. Open Blender (free, available on Windows, macOS, and Linux)
3. Go to File > Import and select your GLB file
4. Verify the model looks correct in the viewport
5. Select the model (click on it, or press A to select all)
6. Go to File > Export > STL (.stl)
7. Choose your save location and click Export STL

That's it. The whole process takes under a minute. Many modern slicers (including recent versions of Cura and PrusaSlicer) also accept GLB directly, so you may not even need the conversion step.

For a full walkthrough of going from photo to finished print, check out our guide on how to 3D print from a pet photo.

Which Format Should You Choose?

Here's a quick decision guide based on what you're trying to do:

Want to 3D print your model? Image to 3D exports GLB, which many modern slicers accept directly. If your slicer only takes STL, import the GLB into Blender and export as STL -- it takes about 30 seconds.

Want to view your model in AR? On iOS, you can view your model in AR via Quick Look directly from the app. On Android, GLB works with Google's Scene Viewer.

Want to edit the model in Blender, Maya, or other 3D software? Import the GLB directly -- all major 3D tools support glTF/GLB import with full texture support.

Want to share the model with someone? GLB is ideal. It's a single file with embedded textures, so nothing gets lost or broken. The recipient can view it on almost any platform without installing specialized software.

Want to post on social media or a 3D gallery? Platforms like Sketchfab accept GLB uploads, and many social platforms are adding native 3D model support using the glTF/GLB standard.

Not sure what you need yet? GLB is the most versatile option and can be converted to other formats later if needed.

How Image to 3D Handles Formats

When you generate a 3D model in Image to 3D -- whether from a photo you've taken or from an AI-generated image -- the app exports your model as a GLB file with embedded PBR textures. GLB is the most universal 3D format and works with game engines, 3D software, AR viewers, slicer software, and web platforms. On iOS, you can also view models in AR via Quick Look directly from the app.

If you need a different format (OBJ for editing, STL for printing, USDZ for sharing), you can convert the GLB in Blender or other free tools in under a minute.

The app offers two quality tiers -- Quick (5 credits) for fast previews, and Pro (13–75 credits) with multiple AI models producing progressively more detailed geometry and textures. Pro models also support optional PBR textures (+9 credits). Higher quality models are especially worthwhile if you plan to edit the model or view it up close in AR, where extra detail makes a noticeable difference. See how it works for more on the conversion process.

The Short Version

3D file formats don't need to be intimidating. Image to 3D exports as GLB, which covers most use cases and is the safest default. If you need OBJ for professional editing, USDZ for Apple AR, or STL for 3D printing, a quick conversion in Blender gets you there in under a minute.

The best approach is to start with GLB for general use, and export to other formats when a specific workflow demands it. Since Image to 3D lets you re-export the same model in any of its three supported formats, you can always come back and grab a different version later.

Ready to turn your photos into 3D models? Check out our complete conversion guide to get started.