Free online STL to OBJ converter

Convert a triangulated STL mesh to OBJ for modeling, materials, and graphics workflows.

Convert STL to OBJ online - free

.stl .obj

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How to convert stl to obj file

September 27, 2026
3D modeling
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A slicer may accept STL for printing while a modeling, animation, or rendering application requires OBJ for mesh editing and material workflows. Converting the file provides an OBJ mesh, but it cannot recover UV maps, textures, or object structure that the STL never contained.

What the STL format is

STL stores a surface as triangular facets and is used by CAD systems, 3D scanners, slicers, 3D printers, and rapid-prototyping workflows. It describes tessellated geometry rather than parametric solids, dimensions, assembly relationships, or editable CAD features.

STL files are commonly ASCII or binary. Each facet includes vertex coordinates and a facet normal; applications may recalculate normals because STL normals are not always reliable. Standard STL does not store UV coordinates, textures, scene hierarchy, part names, or dependable material assignments. Some applications use nonstandard color extensions, but those colors are not portable between STL programs.

What the OBJ format is

OBJ is a text-based mesh format supported by Blender, Maya, 3ds Max, MeshLab, game tools, and rendering software. It can store vertex positions, polygon faces, vertex normals, texture coordinates, object and group names, and material assignments through an accompanying material-library file.

OBJ is useful when a mesh must be inspected, edited, separated into groups, assigned materials, unwrapped for texturing, or transferred between graphics applications. An STL-to-OBJ conversion only changes the representation of the existing mesh; it does not create UV coordinates, textures, materials, or separate parts that were absent from the source.

How to convert the file

Using 101convert

Open the STL-to-OBJ converter on 101convert.com.
Upload the .stl file and start the conversion.
Download the resulting .obj file and open it in the target application.

This option requires no installed software and is available without charge. Check the downloaded mesh and its dimensions before using it for manufacturing or further modeling.

Using Blender

Choose File → Import → STL and select the source file.
Select the imported object. In Edit Mode, select all faces and use Mesh → Normals → Recalculate Outside if faces appear inverted.
Correct the scene scale or orientation if necessary. Use Object → Apply → All Transforms only after choosing the intended dimensions and orientation.
Choose File → Export → Wavefront (.obj). Enable Selection Only to export only the selected object, and enable normals or UV export when those data are present.
Save the result as model.obj. Blender may create model.mtl when material references are exported; keep that file and any referenced image textures beside the OBJ.

Using MeshLab

Choose File → Import Mesh and open the STL file.
Inspect the mesh for holes, non-manifold edges, duplicate vertices, inverted faces, and incorrect scale. Repair or recalculate geometry when required.
Choose File → Export Mesh As, select OBJ, and save the file.
Export normals, vertex colors, or other optional data only if they exist in the source and the receiving application supports them.

Quality and compatibility limits

The conversion preserves the source tessellation. Coarse STL triangles remain coarse in OBJ; increasing polygon density requires subdivision or remeshing, which can smooth edges, alter dimensions, and increase file size.

STL does not reliably embed measurement units, and OBJ has no universal unit declaration. Set the intended units in the destination software and verify a known dimension after import.

A normal single-object STL usually becomes one OBJ mesh. Separate parts, object names, smoothing groups, UV maps, and materials must be created or restored in a modeling application. STL facet normals may be replaced with recalculated vertex normals during import or export, changing shading without changing the geometry.

Binary STL is often smaller than text OBJ, so the converted file may be larger. An OBJ material setup can require .obj, .mtl, and image-texture files; transfer all related files together. Different applications may also vary in their handling of polygon winding, normals, vertex colors, and smoothing.

STL vs OBJ: format comparison

How the STL and OBJ formats compare on the properties that matter most for this conversion.

Comparison of the STL and OBJ file formats
Property	.STL Stereolithography	.OBJ Wavefront OBJ
Geometry	Polygon mesh	Polygon mesh
Materials	No	Limited
Textures	Not supported	Referenced externally
Animation	No	No
Scene hierarchy	No	No
Plain-text readable	Yes	Yes
Typical file size	Small	Medium
Open standard	Partly open	Yes
Introduced	1987	1990
Developer	3D Systems	Wavefront Technologies
MIME type	model/stl	model/obj

Open STL file Open OBJ file

Frequently asked questions

Is the STL to OBJ converter free?

Yes, converting STL to OBJ on 101convert.com is completely free. No registration, email address or installation is required. If you need a higher file size limit or want to convert more files at once, see our plans.

How large can my STL file be?

You can upload STL files up to 50 MB and convert up to 1 files at once in a single batch.

What happens to my uploaded files?

Files are processed automatically and deleted from our servers within a few minutes after conversion. We never view or share your files.

Do I need to install any software to convert STL to OBJ?

No. The STL to OBJ conversion runs entirely online in your browser and works on Windows, Mac, Linux, Android and iPhone.

Did the conversion fail?

In most cases, the cause is an incorrect file format. Please upload a valid STL file for this STL to OBJ conversion. Occasionally, the issue may be on our side. We analyze recurring conversion failures and disable or fix the converter if we detect a defect.

stl to nc1 stl to off

Additional formats for
stl file conversion

Reverse conversion

obj to stl

Convert to obj from
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