Free 3D model converter with no sign-up and no upload
This 3D model converter is free, needs no sign-up or login, and does not upload your models. Your meshes are read and converted inside your browser, so the files never leave your device, and no watermark is added to the result.
Add an OBJ, STL, GLB, glTF or PLY and convert it to any other of those, or to USDZ for AR Quick Look on iPhone and iPad. You can also open 3MF, FBX, Collada (DAE), OFF and 3DS files and export them to OBJ, STL, GLB, glTF, PLY or USDZ. A PNG output gives you a still preview of the model, rendered from a default camera angle.
3D formats store different amounts of information, so what you lose depends on the target. STL keeps geometry only: colours, textures and materials are dropped. OBJ keeps its materials in a separate file. GLB packs a whole scene into one file. Pick the format that matches where the model is going.
Models can be large. The conversion uses your own memory and processor, so a very dense scan or a detailed scene may be slow on a phone or an older computer.
- Free
- No sign-up
- Never uploaded
- No watermark
Your files are converted on your device and never uploaded.
How to convert
- Drag your 3D files onto the page, or choose them with the file picker.
- Check that each file was recognised as the right 3D format.
- Choose the target, for example STL for printing, GLB for the web or USDZ for iPhone AR.
- Adjust any options that appear for that format.
- Press Convert and let the models process on your device.
- Download each result separately, or take a batch as one ZIP file.
Features
- Reads OBJ, STL, GLB, glTF, PLY, 3MF, FBX, Collada (DAE), OFF and 3DS.
- Writes OBJ, STL, GLB, glTF, PLY and USDZ.
- Renders a PNG preview from a default camera angle.
- STL output keeps geometry only and drops colours, textures and materials.
- USDZ output for AR Quick Look on iPhone and iPad.
- Batch conversion with a ZIP download.
- No engine download is needed.
- Free, with no sign-up, no upload and no watermark.
Supported formats
| Format | Read | Write | Notes |
|---|---|---|---|
| Wavefront OBJ.obj | Yes | Yes | Plain-text 3D mesh format from Wavefront, supported by almost every 3D tool. |
| STL (3D).stl | Yes | Yes | The standard input for 3D printing: geometry only, as triangles. |
| GLB.glb | Yes | Yes | Binary glTF: a whole 3D scene in a single file. |
| glTF.gltf | Yes | Yes | JSON-based glTF, usually with separate files for geometry and textures. |
| PLY.ply | Yes | Yes | Polygon File Format, developed at Stanford for 3D scanner data. |
| 3MF.3mf | Yes | No | Writing 3MF is not offered; read it and export OBJ, STL or GLB instead. |
| FBX.fbx | Yes | No | FBX is Autodesk’s proprietary format, so it can be read but not created. |
| Collada (DAE).dae | Yes | No | Collada is read only here; export to GLB or glTF instead. |
| OFF.off | Yes | No | OFF is a simple research format that is read only here; convert it to OBJ or STL. |
| 3DS.3ds | Yes | No | 3DS is a legacy format that is read only here; convert it to OBJ or GLB. |
| USDZ.usdz | No | Yes | Apple’s packaged 3D format for AR Quick Look on iPhone and iPad. |
About the formats
About OBJ and STL
OBJ is a plain-text mesh format from Wavefront that almost every 3D tool supports. Its materials live in a separate MTL file.
STL is the standard input for 3D printing. It stores geometry only, as triangles, with no colour, texture or material data.
About GLB and glTF
glTF is the open format from the Khronos Group, often called the JPEG of 3D. GLB is the binary version: a whole 3D scene in a single file. glTF is JSON-based and usually comes with separate files for geometry and textures.
Both suit the web and real-time viewers, and GLB is the easier one to share because it is one file.
About PLY, 3MF and OFF
PLY, the Polygon File Format, was developed at Stanford for 3D scanner data and can store per-vertex colours. 3MF is a ZIP-based format built for 3D printing that stores colours, materials and print settings. It can be read here but not written.
OFF, the Object File Format, is a very simple text format common in geometry research. It is read-only here.
About FBX, DAE, 3DS and USDZ
FBX is Autodesk's proprietary exchange format for scenes, animation and rigs, and it is read-only here. Collada (DAE) is an XML interchange format from the Khronos Group that glTF has largely replaced, also read-only. 3DS is the legacy format of 3D Studio for DOS, limited to 65,535 vertices per mesh.
USDZ is Apple's packaged format for AR Quick Look. It can be created here but not read, so it is an output choice only.
Choosing a format
For printing, use STL. For the web or an app, use GLB. For moving a mesh between modelling programs, OBJ is the safe middle ground. For iPhone and iPad AR, use USDZ.
Converting from a richer format to STL always drops colour, so keep the original if you need it.
Privacy: how it works
- Your 3D models stay on your device. The page reads each file with the browser's file API, converts it with code running in the tab, and hands the result back as a download. No upload happens, so there is no copy of your file on our servers to protect, delete or leak.
- There is nothing to sign up for and no login. The converter does not ask for an email address, and it does not need to know who you are to do its job.
- You can check the claim yourself: open your browser developer tools, watch the Network tab while a file converts, and you will see no request that carries your file.
- A 3D model is often a product prototype, a scan of a person or a part that is not public yet. Keeping the conversion on your device means it is never copied to a server on the way.
- Textures and other data inside a model file are processed locally with the rest of it.
Tips
- Keep your original FBX or 3MF file. You can read it here, but it cannot be written back, and conversion can drop data.
- Export STL only for printing, and keep a GLB or OBJ copy if you need colour or textures.
- Pick GLB when you want to share a textured model as a single file.
- Remember that an OBJ keeps its materials in a separate MTL file, so keep the two together when you share it.
- Use the PNG output to get a quick thumbnail, then open the model in a viewer to inspect it properly.
- Check units and scale in your target program, because formats differ in how they store them.
- Convert one big scan at a time. A dense mesh uses a lot of memory.
- Open the result in a viewer before you print or publish, and look for flipped faces and missing textures.
Frequently asked questions
Is it really free?
Yes. There is no price, no trial, no credit card and no watermark added to your results. Ulkaa Tool does the conversion with your own device, so there is no server bill to pass on to you.
Are my files uploaded?
No. Your 3D models are read and converted inside your browser and are never sent to Ulkaa or to anyone else. The result is created on your device and you save it from there.
Do I need an account?
No. There is no sign-up and no login. Open the page, add your files and convert. An Ulkaa account is not needed for anything on this tool.
Is there a file size limit?
No limit is set by us. The real limit is your device: the conversion uses your own memory and processor, so very large files can be slow or fail on a weak phone or an older computer. Close other heavy tabs and convert 3D models one at a time if a big batch struggles.