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

| Feature | GLB | OBJ | USDZ | STL | |---|---|---|---|---| | Textures | Embedded (PBR) | Separate files (.mtl + images) | Embedded | None | | File size | Compact | Larger (multiple files) | Compact | Medium | | Best use case | Sharing, AR, web | Professional editing | Apple AR | 3D printing | | Software support | Broad (web, mobile, engines) | Universal (all 3D software) | Apple ecosystem | All slicers/printers | | Animation support | Yes | No | Yes | No | | Image to 3D export | Yes | Yes | Yes | No |

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 lets you export as OBJ when you want to take your model into a 3D editing workflow. This is the right choice if you plan to open the model in Blender, make modifications, or use it as a starting point for a larger project. Check out the features page for a full overview of export options.

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 USDZ so you can take advantage of Apple's AR Quick Look directly from your iPhone or iPad. After converting your photo to a 3D model, export as USDZ and you can immediately preview it in AR -- place it on your table, walk around it, see how it looks at real-world scale. 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 does not export STL directly. The app exports GLB, OBJ, and USDZ. But 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 OBJ or GLB
2. Open Blender (free, available on Windows, macOS, and Linux)
3. Go to File > Import and select your GLB or OBJ 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. If your slicer supports OBJ directly (many modern slicers do, including recent versions of Cura and PrusaSlicer), you can skip the conversion entirely and import the OBJ file straight into your slicer.

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? Export as OBJ or GLB from Image to 3D. Many modern slicers accept OBJ directly. If your slicer only takes STL, import the OBJ or GLB into Blender and export as STL -- it takes about 30 seconds.

Want to view your model in AR? On an iPhone or iPad, export as USDZ for the best AR Quick Look experience. On Android, GLB works with Google's Scene Viewer. If you're sharing with a mixed audience, GLB has the broadest AR support.

Want to edit the model in Blender, Maya, or other 3D software? Export as OBJ. The separate texture files give you full control over materials, and the format has the deepest compatibility with professional editing tools.

Want to share the model with someone? GLB is your best bet. 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? GLB again. 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? Export as GLB. It's 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 produces a textured 3D model that you can export in three formats:

• GLB (default): Single file with embedded PBR textures. Best for sharing, AR on Android, web viewers, and general use.
• OBJ: Multi-file export with separate textures. Best when you want to edit the model in Blender or other 3D software.
• USDZ: Apple's AR format. Best for AR Quick Look on iPhone and iPad.

You can export the same model in multiple formats, so you don't have to choose just one. Generate your model once, then export a GLB for sharing, an OBJ for editing, and a USDZ for AR preview.

The app offers three quality tiers for 3D conversion -- Quick (2 credits), Standard (4 credits), and Ultra (5 credits) -- each producing progressively more detailed geometry and textures. Higher quality tiers 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. GLB covers most use cases and is the safest default. OBJ is your go-to for professional editing. USDZ gives you the best AR experience on Apple devices. And STL remains the standard for 3D printing, even though you'll need a quick Blender conversion to get there from Image to 3D.

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.