Free Online OBJ to STL Converter

Use our fast and 100% free OBJ to STL file converter to convert your OBJ 3D model file to the STL (Standard Triangle Language) format suitable for editing in 3D modelling applications or for 3D printing. Our tool supports batch conversion of your OBJ files with up to 20 files at a time being processed.

Or drag and drop your files here to upload.
A maximum of 20 files can be uploaded at once.

Please note: Your OBJ file, once uploaded to our server will be deleted 15 minutes after upload so please download your converted OBJ file before this time.

Our tool will process all 3D geometry contained within your OBJ file including vertices, faces and normals. As the STL file format does not support materials and textures, if your OBJ file contains references to external texture files these will be ignored. As OBJ files are text-based and the STL file format is binary, the resulting STL file will be much smaller making it faster to store and process the STL file.

How to Convert your OBJ to STL Online?

Here are 2 simple steps to convert your OBJ to STL using our fast and free OBJ converter tool.

Upload your OBJ file

Click the "Upload a OBJ File" button, then select a OBJ to upload. The maximum file size is 100MB.

Download your STL

Click the download link to receive your STL file.

File format information for OBJ and STL

ExtensionOBJ
Full NameWavefront
Type3D Model
Mime Typetext/plain
FormatText
Opens WithMeshLab, CAD Assistant, DAZ Studio

The OBJ file format is a 3D graphics file format used to define complex 3D models, including geometry, materials, and textures. OBJ files are text files, making them human-readable and easy to modify by hand. The downside to this ease of readability is that the files can become rather large when dealing with large or complex 3D models.

As mentioned, the OBJ format stores not only 3D model geometry but also materials and textures. These materials are usually defined in a separate file with the MTL file extension and specify geometry rendering details such as diffuse and specular color, transparency, and much more.

The OBJ material file can also reference external texture files. These are usually JPEG or PNG files; however, these can be older formats, such as TGA. Where materials are used, the OBJ file will also contain material names preceding the geometry faces they should be applied to. If textures are referenced, the geometry will also contain texture coordinates (UV) for each vertex.

OBJ Converter Capabilities

Our OBJ 3D Model/Mesh tool does not support any color material data contained within OBJ files so the converted file will not contain any color information.

ExtensionSTL
Full NameStandard Triangle Language
Type3D Model
Mime Typeapplication/vnd.ms-pki.stl
FormatText
Opens WithBlender, MeshLab, CAD Assistant, DAZ Studio

The STL, or Standard Triangle Language, file format has been around since the '80s and is supported by most modern 3D modelling applications. In particular, the STL format has become something of a standard format within the area of 3D printing, despite the rise of more modern formats such as 3MF.

STL files come in two flavours: binary or text format. The text format is human-readable, making it easy to perform manual edits, but can lead to very large file sizes. As you can imagine, the binary format is much more compact and represents the majority of the STL files you are likely to encounter.

The format itself is very simple; the 3D model is represented by a sequential list of triangles, with each triangle defined with 3 points consisting of their X, Y, and Z positions, along with an additional vector that contains the face normal (the direction the face is pointing). There is an additional attribute block for each triangle; however, this is largely unused and thus unsupported.

STL Converter Capabilities

Our 3D conversion tool does not support color/material information in STL files so your file will not contain any color information.

Information for converting from OBJ to STL

Your OBJ file will be converted to a STL file using our unified 3D model and mesh conversion tool. Our OBJ 3D tool performs accurate conversions of 3D elements such as vertices, faces, normals and relevant material information. Our tool will not attempt to transfer any color information if present in your OBJ file, your final 3D model will contain geometry data only.

Frequently Asked Questions

How can I convert my OBJ file to STL?

First click the "Upload..." button, select your OBJ file to upload. Your OBJ file will be uploaded to our servers. When the OBJ to STL conversion has completed, you can download your STL file straight away.

How long does it take to convert my OBJ to STL?

We aim to process all OBJ to STL conversions as quickly as possible, this usually takes around 5 seconds however this can be longer for certain files, so please be patient.

How accurate is the OBJ to STL conversion?

We aim to provide the best conversion experience. Our tools are under constant review and development with new features being added every week.