OBJ to 3MF Converter
Convert a OBJ 3D model to 3MF online. A plain-text mesh that most 3d software reads, with materials kept in a separate .mtl file becomes a ZIP+XML print package that records colour, materials and real-world units.
Complete the security check to begin
About Converting OBJ to 3MF
OBJ is a widely supported 3D geometry format that stores vertices, faces, texture coordinates and normals as plain text. It is a common interchange format between modelling, rendering and CAD applications, optionally pairing with an .mtl file for materials. When you need to move away from OBJ, the usual reason is simple: materials live in a separate .mtl file.
Converting your OBJ 3D model to 3MF solves that. 3MF is a modern 3D-printing format built to replace STL. It stores the mesh plus colour, materials, units and print settings in a compact ZIP-based package, fixing many of STL’s long-standing shortcomings. In practice you gain carries colour, materials and units and compact zip-based package. PrivConvert runs the whole OBJ-to-3MF conversion in server memory and deletes your file the instant the 3MF is ready — nothing is stored, logged or reused.
When this conversion helps
- You need carries colour, materials and units
- You need compact ZIP-based package
- You need backed by major printer and CAD vendors
- Sharing a OBJ 3D model with someone whose software expects 3MF
Tips for best results
- Files up to 250 MB are supported, and you can batch-convert several OBJ files at once; each is processed privately and deleted immediately.
How to Convert OBJ to 3MF Online
Converting OBJ to 3MF with PrivConvert takes three quick steps and no software to install. What you gain with 3MF: carries colour, materials and units.
Drag and drop your file into the upload area, click to browse your device, or paste a URL to a file hosted online. You can upload files up to 250 MB and batch convert up to 20 files at once.
Once uploaded, the conversion from OBJ to 3MF starts automatically. The process runs entirely in an isolated environment - your data never leaves the secure pipeline.
Your converted file is ready instantly. Click the download button to save it to your device. The file is deleted from memory immediately after download.
Private by design, not as an afterthought
Most online converters upload your files to a server, keep them for days, and may mine them for AI training or resale. PrivConvert was built the opposite way — around your privacy.
We never keep a copy. Once your 3MF is delivered, both the original and the result are gone — there is nothing left to leak or misuse.
Every conversion runs in its own locked-down process with no network access, so files can never leak or interfere with one another.
Your files are handled entirely by automated code. No staff, partner or AI model ever reads, stores or trains on your data.
Files are processed in volatile memory (RAM) and purged the instant your download is ready — nothing is ever written to disk, cached or backed up.
OBJ vs 3MF - Format Comparison
| Feature | OBJ | 3MF |
|---|---|---|
| File extension | .obj | .3mf |
| Full name | Wavefront OBJ | 3D Manufacturing Format |
| Introduced | 1990 | 2015 |
| Encoding | Text | Binary |
| Editable | No | No |
| Open standard | Yes | Yes |
| Supported by PrivConvert | Yes (as input) | Yes (as output) |
| Privacy-safe conversion | In-memory, zero storage | |
| Max file size | 250 MB per file | |
| Batch support | Up to 20 files simultaneously | |
Built for people who value their privacy
From one-off files to daily batches, thousands of people rely on PrivConvert precisely because it keeps nothing once the job is done.