Convert 3D files online

Free converter for STL, OBJ, PLY, GLB/glTF, 3MF, and STEP. Pick an output format, convert in your browser, and keep your files on your device.

Convert the attached model to STL (binary)

Files are processed entirely in your browser. Nothing is uploaded to a server.

Any 3D edit is just a prompt away.

Supported conversions

Input: STL, OBJ, PLY, GLB/glTF, 3MF, FBX, 3DM, and the CAD formats STEP (.step / .stp) and IGES (.iges / .igs). Output: binary STL for 3D printing, OBJ for Blender and other DCC tools, PLY for scanning pipelines, or GLB for the web and game engines. Everything is processed locally in your browser, so nothing gets uploaded.

Multi-part files are merged into a single mesh. Materials and textures are dropped, because the pipeline works on plain geometry.

All conversion paths

Frequently asked questions

Can I convert STL to STEP here?

Not yet. STL is a triangle soup while STEP describes exact CAD surfaces, so a faithful conversion needs real surface reconstruction. If you need a parametric CAD model, describe the part in GrandpaCAD chat and it will generate clean CAD geometry you can export.

Why did my textures disappear?

STL and PLY (as exported here) only store geometry. If you need colors and materials preserved, keep the original textures in your source tool and re-apply them after conversion.

Is there a file size limit?

Models up to 8 million triangles are supported. STL files can be any size below that; other formats stop at 300 MB. Both limits exist because the conversion runs in your browser tab. For heavier models, run the reduce tool first: decimate, then convert.

More free 3D file tools

View a model Repair a model Reduce file size Measure a model Scale a model Split a model Mirror a model Print orientation Print weight & cost

Describe a part. Get a printable model.

GrandpaCAD turns a text prompt into a ready-to-print 3D model. Functional parts, organic shapes, multi-color prints. No CAD skills needed.

"Model a 40 mm rounded keychain tag with raised text that says HELLO, ready to print."

3 free generations, no card required

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Convert 3D files online

Free converter for STL, OBJ, PLY, GLB/glTF, 3MF, and STEP. Pick an output format, convert in your browser, and keep your files on your device.

Convert the attached model to STL (binary)

Files are processed entirely in your browser. Nothing is uploaded to a server.

Any 3D edit is just a prompt away.

Supported conversions

Multi-part files are merged into a single mesh. Materials and textures are dropped, because the pipeline works on plain geometry.

All conversion paths

Frequently asked questions

Can I convert STL to STEP here?

Why did my textures disappear?

STL and PLY (as exported here) only store geometry. If you need colors and materials preserved, keep the original textures in your source tool and re-apply them after conversion.

Is there a file size limit?

More free 3D file tools

View a model Repair a model Reduce file size Measure a model Scale a model Split a model Mirror a model Print orientation Print weight & cost

Describe a part. Get a printable model.

GrandpaCAD turns a text prompt into a ready-to-print 3D model. Functional parts, organic shapes, multi-color prints. No CAD skills needed.

"Model a 40 mm rounded keychain tag with raised text that says HELLO, ready to print."

3 free generations, no card required