STL to OBJ Converter
Convert an STL 3D model to a Wavefront OBJ file for editing, rendering and material work.
Complete the security check to begin
About Converting STL to OBJ
STL is the universal 3D-printing format. It describes a model as a raw triangle mesh — just the surface geometry, with no colour, texture or units. Nearly every slicer and 3D printer accepts it, which is why it is the default export from most CAD tools for printing. When you need to move away from STL, the usual reason is simple: no colour, texture or material data.
Converting your STL 3D model to OBJ solves that. 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. In practice you gain human-readable text and supports texture coordinates and normals. PrivConvert runs the whole STL-to-OBJ conversion in server memory and deletes your file the instant the OBJ is ready — nothing is stored, logged or reused.
When this conversion helps
- You need human-readable text
- You need supports texture coordinates and normals
- You need read by almost every 3D application
- Sharing a STL 3D model with someone whose software expects OBJ
Tips for best results
- Files up to 250 MB are supported, and you can batch-convert several STL files at once; each is processed privately and deleted immediately.
How to Convert STL to OBJ Online
You can convert STL to OBJ right in your browser in under a minute. What you gain with OBJ: human-readable text.
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 STL to OBJ 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.
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.
Every upload and download is protected with TLS 1.3, so your 3D model cannot be intercepted on the way to the server or back to you.
Convert instantly with no sign-up, no email and no profiling cookies. We never build a profile around you or the files you convert.
Runs in any modern browser on Windows, macOS, Linux, Android and iOS — no install, plugin or desktop software needed.
STL vs OBJ - Format Comparison
| Feature | STL | OBJ |
|---|---|---|
| File extension | .stl | .obj |
| Full name | Stereolithography | Wavefront OBJ |
| Introduced | 1987 | 1990 |
| Encoding | Binary | Text |
| 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 | |
A converter you do not have to worry about
PrivConvert handles thousands of conversions every day for developers, designers and privacy-conscious people who need a 3D model converted without handing over a permanent copy.