Convert STL to OBJ (Free)
Also converts GLB, PLY, USDZ, 3MF, WRL, STEP from the same file.
Runs in your browser. No upload, no signup, nothing to install.
Also from Innerscene: Circadian Lab, a free lighting calculator for room illuminance, melanopic EML, and glare.
How to convert STL to OBJ
- 1
Open your .stl file
Drag it onto the viewer above, or click "Open an STL File". Files up to 200 MB open directly; the parse runs in a worker so the page stays responsive.
- 2
Pick Wavefront OBJ in the Export menu
Click Export in the toolbar, then OBJ (.obj).
- 3
Download
The .obj is written in the browser and saved straight to your downloads folder. No queue, no email, no watermark.
What survives the conversion
A file conversion is a translation, and formats do not carry the same things. Here is exactly what moves from STL into OBJ, and what does not.
| Geometry | Kept | Both formats store triangle meshes, so the shape transfers directly. |
|---|---|---|
| Colors and materials | N/A | STL files carry no color, so the OBJ comes out in the viewer’s default material. You can color it in the destination application. |
| Units and scale | Dropped | OBJ stores no unit. Coordinates are written in meters, so set the import unit to meters if the destination asks. |
What the OBJ writer emits: OBJ plus a companion MTL, zipped together. Each layer becomes an object block and each mesh a named group with its material color.
The source: Stereolithography (.stl)
A single triangle soup. STL stores no color, no units, no parts and no layers, only the surface.
The target: Wavefront OBJ (.obj)
The lowest common denominator of 3-D interchange. Practically every 3-D application reads it.
Opens in: 3ds Max, Maya, Rhino, Cinema 4D, Blender, MeshLab.
Your file never leaves your computer
Both the STL parser and the OBJ writer are JavaScript and WebAssembly running in your own browser tab. There is no upload step, no server-side conversion queue, and no copy of your file anywhere but your machine. That matters for drawings under NDA, for client work, and for anything you would not email to a stranger.
Frequently asked questions
▶Is this STL to OBJ converter free?
Yes. No signup, no watermark, no per-file limit and no paid tier. Innerscene.
▶Is my STL file uploaded anywhere?
No. The file is read with the browser file API and converted in the same tab. Nothing is sent to a server unless you explicitly click Share, which is a separate, opt-in feature.
▶Will my colors and materials survive the OBJ export?
STL files carry no color, so the OBJ comes out in the viewer’s default material. You can color it in the destination application.
▶Will the OBJ open at the right size?
OBJ stores no unit. Coordinates are written in meters, so set the import unit to meters if the destination asks.
▶How large an STL file can I convert?
Up to 200 MB, and the ceiling adapts to how much memory your device reports. The conversion runs on your own hardware, so a desktop with plenty of RAM will handle more than a phone.
▶Can I convert OBJ back to STL?
Yes, the other direction works too. Bear in mind that anything the first conversion dropped is not restored by converting back. OBJ → STL
▶Which browsers does it work in?
Chrome, Edge, Firefox and Safari, on Windows, macOS, Linux, iOS and Android. No plugin and no extension.
Convert STL to something else
Convert something else to OBJ
Or start from the universal 3D viewer.