OBJ to STL Converter | STL to OBJ Online

Convert OBJ to STL for 3D printing in your browser, with Y-up to Z-up rotation, unit scaling and binary or ASCII output. Converts STL to OBJ too. No upload.

Also known as: obj to stl · obj to stl converter · convert obj to stl online · stl to obj · stl to obj converter · wavefront obj to stl · convert stl to obj online · obj to stl for 3d printing · blender obj to stl · obj to stl free

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OBJ Input

Files never leave your browser

Drop an OBJ file here, or click to browse

Wavefront OBJ from Blender, Maya, 3ds Max, SketchUp, ZBrush or a 3D scan app. Materials and textures are not needed. Up to 1 GB.

Units in the OBJ

Extra scale factor

Y-up to Z-upRotate 90 degrees about X so a Blender or game model stands upright in a slicerPlace on the bedMove the lowest point to Z = 0Center on X and YPut the middle of the model at the origin

STL format

OutputObjects or groups in the OBJ can be saved as separate STLs

STL Output

Your STL preview will appear here

Open an OBJ file to see it on a print bed, upright and in millimeters, with its size, triangle count and every polygon split into triangles. Then download one STL or a ZIP with one STL per object.

About OBJ to STL Converter

OBJ to STL Converter is used to turn Wavefront OBJ models from Blender, Maya, SketchUp or a 3D scan app into STL files a slicer can print, and to turn STL files back into OBJ. It splits every polygon into correct triangles, rotates Y-up models to stand upright on a Z-up print bed, scales meters, centimeters or inches to millimeters, and runs in your browser without uploading anything.

Key Features

Triangulates quads and n-gons by ear clipping in each face's own plane, so concave L and U shaped faces stay correct
Rotates Y-up OBJ exports to Z-up so the model stands upright in Bambu Studio, PrusaSlicer, Cura and other slicers
Scales from meters, centimeters or inches to millimeters with an extra scale factor, then places the part flat on the bed
Writes binary or ASCII STL as one merged file or a ZIP with one STL per OBJ object or group
Converts STL to OBJ with shared vertices, optional flat face normals and Z-up to Y-up for Blender, Unity and three.js
3D preview on a millimeter grid with the size in millimeters and inches before you download

Use Cases

Print a model sculpted in Blender, which writes OBJ in meters with Y up, without it coming out 1,000 times too small or lying on its back
Turn an OBJ from a photogrammetry or LiDAR scan app on an iPhone into an STL for a Bambu Lab, Prusa or Creality printer
Split a multi-part OBJ kit into one STL per part for a print farm or a service such as Craftcloud or Xometry
Bring an STL from Thingiverse or Printables into Blender, Unity or a three.js scene as an OBJ with Y up
Hand an ASCII STL to an older CAM or CNC program that cannot read binary STL

Supported Formats

OBJ (Wavefront, v and f with any index form)

STL (binary)

STL (ASCII)

ZIP of STL files (output)

Related Keywords

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Why is my STL tiny or lying on its side after converting from OBJ?

STL stores no unit, and slicers read its numbers as millimeters. Blender writes OBJ in meters by default, so a 50 mm part arrives as 0.05 and looks 1,000 times too small: set the OBJ units to meters. Most 3D apps also treat Y as up, while printers treat Z as up, so a Y-up model lies on its back until it is turned 90 degrees about the X axis, which the Y-up to Z-up option does.

Privacy & Security

All processing happens locally in your browser. Your data never leaves your computer, ensuring complete privacy and security.

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Frequently asked questions

What is OBJ to STL Converter used for?

Convert OBJ to STL for 3D printing in your browser, with Y-up to Z-up rotation, unit scaling and binary or ASCII output. Converts STL to OBJ too. No upload.

Is OBJ to STL Converter free to use?

Yes. OBJ to STL Converter is completely free with no usage limits, and there is no paid tier required to use it.

Do I need an account to use OBJ to STL Converter?

No. OBJ to STL Converter works immediately in your browser with no signup, login, or email address required.

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