Convert OBJ to STL Online
Convert your 3D OBJ to STL file that can then be sent straight to a 3D printer or opened in most 3D editing applications such as Blender. Our OBJ to STL converter works with all OBJ files and will convert all 3D geometry contained within the file to STL.
How to Convert your OBJ to STL Online?
Here are two simple steps to convert your OBJ to STL using our free OBJ to STL converter.
1
Upload an OBJ File
Click the 'Upload an OBJ File' button and select an OBJ file to upload. The maximum file size is 100MB. You can also drag and drop your OBJ file directly onto the converter. If your OBJ file has separate material (MTL) and texture files, you can upload them together or within a ZIP archive for complete OBJ to STL conversion.
2
Download your STL File
Once your OBJ file is uploaded, the OBJ to STL conversion will start automatically. Click the download link once the OBJ to STL conversion completes to receive your STL file. The entire OBJ to STL conversion process typically takes just a few seconds.
Converting OBJ to STL, How Does It Work?
Step 1: Read the Source OBJ File
In its simplest form, an OBJ file is a plain text file containing human-readable 3D data such as vertices, faces, normals, and more. When our OBJ to STL converter reads this 3D data, all we are interested in are the vertices, faces, and normals, as this is the only data that can be accurately converted into the final STL file. The OBJ file can contain other data, such as material definitions and textures, that describe how a particular set of 3D geometry should be rendered. As we are creating an STL file, which does not support materials and textures, we will be ignoring this data if it is present in the OBJ file during OBJ to STL conversion.
Step 2: Process File Data
With the OBJ file data read, our OBJ to STL converter generates an internal representation of the full 3D model and will attempt to fix any geometry issues encountered. Along with repairing any issues with the 3D model, the tool will remove any duplicated vertices and prepare the model for exporting to STL format. This ensures accurate OBJ to STL conversion results.
Step 3: Saving to the STL Format
The STL format has been around for many years and has become not only a standard format for storing and transmitting 3D models but also a standard format for 3D printing. STL files can be opened in most modern 3D editing applications without further processing. To enable the saving of the model, our OBJ to STL converter now needs to take the in-memory 3D model we have created in step 2 and convert this to the STL format. As the STL format supports only simple triangles with a single directional normal, if your OBJ contains vertex normals, these will be recalculated into a single-face normal during OBJ to STL conversion. To ensure an efficient file size, our OBJ to STL converter will always save any STL file in its binary format.
File Format Information from OBJ to STL
Format Info for OBJ
Type:
Tools:
Open With:
The OBJ file format, originally created by Wavefront Technologies and later adopted by many other 3D software vendors, is a simple text-based file format for describing 3D models/geometry. This data can include vertices, faces, normals, texture coordinates, and references to external texture files. As the format is text-based, it is relatively straightforward to parse in 3D modeling applications. A downside of the text-based format is that the files can be rather large compared to similar binary formats such as STL and compressed files such as 3MF. When converting OBJ to STL, our converter extracts the geometric mesh data while preserving the 3D model structure. If your OBJ file is uploaded with accompanying MTL and texture files, these will be applied to the conversion process, though material and texture information is not preserved in the final STL output.
Format Info for STL
Full Name:
Standard Triangle Language
Type:
Mime Type:
application/vnd.ms-pki.stl
Tools:
Open With:
The STL file format has its roots in the 1980s and is the native file format for 3D Systems stereolithography CAD software. The format defines a triangulated mesh with vertices and faces and is a popular format for sharing 3D printable model files. There were several formats that attempted to extend the STL format, namely SolidView and VisCAM, whose formats included limited 15-bit color information for each mesh face, which is often ignored by most modern 3D software. The STL format can be either text or binary; our OBJ to STL converter supports both formats. The standard STL file format does not support colored faces, vertices, or texture information. The STL file generated by the OBJ to STL converter will contain only raw mesh/triangle data by default, which is perfect for 3D printing. The tool also has the option to save the file to one of the non-standard formats that support colored faces, such as VisCAM and SolidView, which is perfect if you want to further process the STL in software that supports these formats.
A Comparison of OBJ and STL File Formats for OBJ to STL Conversion
OBJ Features
Mesh Geometry (Vertices and Faces)
OBJ format stores geometry as a collection of vertices and faces, with the vertices being drawn from a common pool, meaning a 3D object can use the same vertex on several faces without needing to define it multiple times. This efficient structure is preserved during OBJ to STL conversion.
Vertex Normals
OBJ files support per-vertex normals, taken from a single common list that can be shared amongst several faces within the 3D object. When converting OBJ to STL, vertex normals are recalculated into face normals.
Face Normals
OBJ format supports face normals, though these can be calculated automatically. During OBJ to STL conversion, face normals are preserved in the STL output.
Vertex Colors
OBJ format supports vertex colors, allowing colorful 3D models. However, when converting OBJ to STL, color information is not preserved as STL doesn't support colors.
Face Materials
OBJ files have extensive support for different object materials, including color and texture surfaces via MTL files. Material information is not preserved when converting OBJ to STL.
Textures
OBJ format supports textures with texture coordinates and references to external texture files (PNG, JPG, TGA formats). Textures are not preserved when converting OBJ to STL.
Multiple Objects Per File
OBJ files can contain multiple 3D objects within the same file. Our OBJ to STL converter processes all objects from OBJ files.
Smaller File Size
When comparing STL binary format to OBJ format (text-based), using a file that contains only mesh geometry with no textures or materials, the OBJ file usually offers the smallest file size due to shared vertex data. This efficiency is maintained during OBJ to STL conversion.
STL Features
Mesh Geometry (Vertices and Faces)
STL files contain 3D mesh geometry defined by vertices and triangular faces. In the STL format, each face has its own set of 3 vertices that cannot be re-used by other faces, which can result in larger file sizes compared to OBJ format.
Vertex Normals
STL format does not support vertex normals. When converting OBJ to STL, vertex normals are recalculated into face normals.
Face Normals
STL files support face normals, which determine the front and back of each triangle. Face normals are essential for proper 3D model visualization in OBJ to STL converted files.
Vertex Colors
Standard STL format does not support vertex colors. Color information from OBJ files is lost during OBJ to STL conversion. Some non-standard formats like VisCAM and SolidView support limited color, but these are not widely supported.
Face Materials
STL format does not officially support any material or texture capability. Material definitions from OBJ files are not included when converting OBJ to STL.
Textures
STL format does not support textures. Texture information from OBJ files is not preserved during OBJ to STL conversion.
Multiple Objects Per File
STL format is a simple list of triangles with limited ability to separate out individual 3D objects within a scene. Our OBJ to STL converter handles multiple objects from OBJ files.
Binary and Text Formats
STL format supports both binary and text (ASCII) versions. Our OBJ to STL converter saves files in binary format for efficiency, which is perfect for 3D printing.
FAQ
Frequently Asked Questions About OBJ to STL Conversion
Have questions about converting OBJ to STL? Find answers below or contact us for support.
1
What does OBJ to STL conversion do?
OBJ to STL conversion transforms your OBJ (Wavefront OBJ) files into STL (Stereolithography) format. STL is the most widely used format for 3D printing, and our OBJ to STL converter ensures all geometric data is preserved during the conversion process. The OBJ to STL conversion extracts the geometric mesh while preserving the 3D model structure.
2
How do I convert OBJ to STL?
Converting OBJ to STL is simple: click the 'Upload an OBJ File' button and select your OBJ file. The OBJ to STL conversion will start automatically, and once complete, you can download your STL file. The entire OBJ to STL conversion process takes just a few seconds. You can also drag and drop your OBJ file directly onto the converter.
3
Do I need special software to convert OBJ to STL?
No software is needed to convert OBJ to STL. Our OBJ to STL converter is completely web-based and works in any modern browser on Windows, Mac, Linux, Android, iOS, or mobile devices. Simply upload your OBJ file and convert online - no downloads or installations required for OBJ to STL conversion.
4
What is the difference between OBJ and STL formats?
OBJ is a 3D file format that includes mesh data, texture coordinates, and material information. STL is a simpler format containing only triangular mesh data. Converting OBJ to STL extracts the geometric mesh while preserving the 3D model structure. OBJ files support materials and textures via MTL files, while STL format does not support materials or textures. OBJ format uses shared vertices for efficiency, while STL format duplicates vertex data for each face.
5
Will textures be preserved when converting OBJ to STL?
STL format only supports geometric mesh data, so textures from OBJ files are not included in the STL output when converting OBJ to STL. However, all geometric details and mesh structure are fully preserved during OBJ to STL conversion. Material and texture information from OBJ files is lost in the OBJ to STL conversion process.
6
Is my OBJ file safe when converting to STL?
Yes, your privacy is important when you convert OBJ to STL. We don't store your OBJ files after conversion. Converted STL files are stored for 4 hours, then automatically deleted. You can also delete files immediately using the delete button after OBJ to STL conversion.
7
What is the maximum OBJ file size I can upload?
You can upload OBJ files up to 100MB for OBJ to STL conversion. Larger files may take longer to process, but our OBJ to STL converter handles files of various sizes efficiently. For batch OBJ to STL conversion, you can upload up to 25 files at once.
8
My OBJ file contains materials and textures; how do I upload these?
If your OBJ file has separate material (MTL) and texture (PNG, JPG, etc.) files, you can drag and drop these onto the upload tool along with the main OBJ file. Our OBJ to STL converter will intelligently detect which of these additional files belongs to the OBJ file. Alternatively, you can place these additional files, along with the OBJ file, within a ZIP or other compressed archive file and upload that for OBJ to STL conversion.
9
What is an STL file?
The STL file format describes an unstructured triangulated surface of triangles using a 3D Cartesian coordinate system. STL files do not contain any scale information, and the units are arbitrary. STL is the most widely used format for 3D printing. When you convert OBJ to STL, the resulting STL file contains triangulated mesh data perfect for 3D printing.
10
What STL formats can I convert to from OBJ?
Our OBJ to STL converter saves all STL files in binary format by default, which is the most efficient format for 3D printing. Optionally, our OBJ to STL converter allows you to save to non-standard color STL formats such as VisCAM and SolidView if you want to further process the STL in software that supports these formats.
11
I have several OBJ files; can I batch convert my OBJ to STL?
Yes! Our OBJ to STL converter supports full batch conversions. You can upload up to 25 OBJ files at a time. Our OBJ to STL converter will convert them all as quickly as possible. Once completed, you can either download the STL files individually or download them all in a single ZIP file after OBJ to STL conversion.
12
How long does it take to convert my OBJ to STL?
We aim to process all OBJ to STL conversions as quickly as possible. Most OBJ to STL conversions usually take around 5 seconds, but can be more for larger, more complex OBJ files, so please be patient. All processing happens on our servers, so you don't need a high-spec computer for OBJ to STL conversion.
13
How accurate is the OBJ to STL conversion?
We aim to create the most accurate OBJ to STL conversions with our tools. Our OBJ to STL converter is under constant development with new features and improvements being added regularly to ensure maximum compatibility and accuracy. The OBJ to STL conversion preserves all geometric mesh data accurately.
14
Can I convert my OBJ to STL on Windows, Linux, Android, iOS or Mac OS?
Yes! Our OBJ to STL converter will run on any system with a modern web browser. No specialist software is needed to run any of our OBJ to STL conversion tools. You can convert OBJ to STL on Windows, Mac, Linux, Android, iOS, or any mobile device.
15
Can I convert OBJ to STL for 3D printing?
Yes! 3D printer slicer software generally does not support the OBJ file format, but slicer software can handle files formatted to the STL specification. Our OBJ to STL converter can convert your OBJ file into an STL file suitable for loading into the 3D slicer software of your choice. As STL files do not support material colors or textures, our OBJ to STL converter will not process these, resulting in a single STL file suitable for use with most 3D slicer software.