8 Best OBJ to STL Converters

OBJ and STL file formats are both quite popular in the 3D printing sphere. Each has its unique attributes. The OBJ format is compact, storing shape, texture, and color information for 3D objects, making it suitable for high-spec 3D printers and slicers. It supports high-resolution graphics without increasing file size, excluding external factors like lighting. The STL file format, on the other hand, is primarily used by mid- to low-range 3D printers and focuses on geometric data to describe an object's surface shape without details on color or texture. It's widely accepted and reliable for basic shape communication. The main advantage of OBJ over STL is its ability to include color and texture directly in the file, enhancing the rendering of complex, multicolored models. Converting OBJ to STL is straightforward, with various options available including: free software tools, online converters, and paid tools. 

Listed below are 8 best OBJ to STL converters:

1. Tinkercad®

Tinkercad® is a free, web-based 3D modeling tool developed by Autodesk, designed for beginners in 3D design. Its key features include an intuitive interface with drag-and-drop functionality, making it simple for users to create 3D models from basic shapes. Tinkercad® supports direct export to STL format. It can, however, only convert two file formats to STL: OBJ and SVG file formats. While its accessibility and ease of use are significant pros, the software's limited functionality for more complex modeling tasks is a con. Tinkercad® differs from more sophisticated modeling software by focusing on simplicity and education, which is ideal for newcomers to 3D design. Its cloud storage feature enables users to store their conversions for future use. On the downside, Tinkercad® requires a continuous internet connection for use, and its narrow range of convertible file types may limit its competitive edge against other conversion tools. User feedback generally highlights Tinkercad's® user-friendly interface and educational value, though advanced users may find it lacking in features such as: limited rendering options, no lighting features, and limited color options. The platform's ratings are consistently high, especially among beginners and educators.

2. Blender®

Blender® is an open-source 3D creation suite that supports the entire 3D pipeline, including: animation, simulation, modeling, rigging, rendering, compositing, and motion tracking. Its comprehensive tool set makes it suitable for professionals and hobbyists alike in both 3D design and animation. This 3D modeling software supports 15 different file formats, including: common types like: SVG, OBJ, PLY, and DAE. With the addition of community add-ons, Blender's® capabilities extend to even more file formats. Blender® is compatible with Windows, macOS, and Linux, and offers mobile-friendly capabilities. Blender's® ability to export models to STL format is particularly beneficial for 3D printing. The software's major advantages include its versatility and zero cost, but it has a steep learning curve that can be challenging for beginners. Unlike simpler tools like Tinkercad®, Blender® offers advanced features that cater to a wide range of 3D design needs, from animation to game development. Blender® is free for all users, which significantly contributes to its popularity. User feedback often praises Blender® for its professional-grade features and flexibility, though newcomers frequently mention its complexity as a drawback.

3. FreeCAD®

FreeCAD® is one of the best OBJ to STL conversion software offerings. This free, open-source parametric 3D CAD modeler is compatible with Windows, Linux, and macOS, offering an intuitive interface that simplifies the process of importing and converting 3D models. Beyond STL, FreeCAD supports a range of CAD formats including: DAE, IGES, PLY, STP, and IFC, allowing for versatility in design work. Users can easily import models in OBJ format and then use the platform’s export feature to save them in STL file format. Before converting, you have the option to modify the OBJ model using different tools. These include: shaping, scaling, moving, rotating, mesh creation from shapes, smoothing, mesh cutting, and trimming. Though FreeCAD® has an extensive range of features, user feedback highlights that the program is a bit buggy and inconsistent. Some users point out that it’s ideal for simple projects, individuals, or small companies, but that it is limited in terms of larger, more-complex designs. Users also mention that it has a steep learning curve for new users. Despite this, its ratings reflect a strong appreciation for its capabilities and open-source model.

4. Autodesk Fusion 360®

Autodesk Fusion 360® is a comprehensive, cloud-based CAD, CAM, CAE, and PCB software platform that facilitates product design and manufacturing. It integrates various design tools, including: 3D modeling, simulation, and collaboration features. It is compatible with both Windows OS and macOS. Fusion 360® offers a 30-day free trial, followed by an annual subscription fee for professionals of $680 for one user. There’s also the option to pay $85 a month or a 3-year subscription for $2,040. It supports conversion across 35 different file formats, including well-known CAD formats like: PRT, STP, and IGS. The ability to export to STL and other formats, combined with its cloud-based collaboration capabilities, are among Fusion 360's key advantages. However, its subscription-based pricing model may deter some users. Fusion 360® differs from other CAD tools by offering an all-in-one solution for product development, with a focus on collaborative projects. While it offers a free version for students, educators, and hobbyists (for home-based and non-commercial projects), professional users must subscribe. User feedback is generally positive, praising its comprehensive tool set and cloud capabilities, though some mention performance issues on less-powerful machines. The learning curve can also be quite steep. 

5. OpenSCAD

OpenSCAD is 3D CAD software that emphasizes script-based modeling, allowing users to create solid 3D CAD objects with precise control over the modeling process. OpenSCAD is particularly useful for designing mechanical parts and for any project in which precise dimensions are crucial. While the script-based approach offers unmatched precision and repeatability, it requires users to be comfortable with coding, which can be a significant barrier for those accustomed to graphical interfaces. Unlike GUI-based CAD programs, OpenSCAD caters to a niche audience that values the control provided by textual description over visual modeling. User feedback often reflects an appreciation for OpenSCAD's precision and control, with the primary critique being its steep learning curve for those new to scripting.

It is available for free and offers a somewhat unconventional yet effective method for converting OBJ files to STL format. This functionality, only available for version 2015.03-2 and up, makes use of the import() command, which enables users to bring external 3D geometries, such as those in OBJ format, into the OpenSCAD environment. In the Open File dialog of OpenSCAD, the file type filter may show only OpenSCAD files, but replacing the file name with a wildcard (e.g., *.obj) allows browsing to additional file types. Once imported, these geometries can be rendered within OpenSCAD and subsequently exported as STL files, a process that essentially allows for file format conversion.

6. MeshLab®

MeshLab® is an open-source system designed for processing and editing unstructured 3D triangular meshes. This software is available for Windows, Mac, and Linux. It offers a wide range of features for editing, cleaning, healing, inspecting, and converting meshes, making it a valuable tool for handling raw 3D data. While MeshLab® excels in mesh processing, its specialized focus means it may not be the best choice for general 3D modeling tasks. MeshLab's® distinct advantage lies in its comprehensive mesh-editing capabilities, which set it apart from more generalized 3D modeling software. As a free tool, it attracts users in fields like: 3D scanning, 3D printing, and scientific research who require detailed mesh processing. 

MeshLab® can be used to convert OBJ files to STL format. It simplifies the process by allowing users to import an OBJ file, edit it using a variety of tools such as: translation, rotation, and scaling, and then export it as an STL file with options like binary encoding. User feedback for MeshLab® is generally positive, with users valuing its extensive mesh-processing tools, though some critique the user interface for being less intuitive compared to other 3D modeling platforms.

7. Wings 3D

Wings 3D is a free, open-source 3D modeling software that focuses on subdivision modeling. It provides a wide range of modeling tools, allowing for the creation of detailed 3D models through an intuitive interface. Wings 3D supports exporting models to STL format, making it suitable for 3D printing projects. Beyond OBJ and STL, it supports a wide array of file formats, such as: 3DS, PLY, and DAE. The process for converting OBJ files to STL is straightforward: users simply import an OBJ file through the File > Import > Wavefront (.obj) menu, utilize a variety of editing tools to modify the model as needed, and then export the file as STL via the File > Export > Stereolithography (.stl) option. 

Wings 3D lacks the advanced features found in more complex software like Blender® or Fusion 360®. Some users wish for more advanced features and better integration with other software tools.

8. Convert CAD Files

Convert CAD Files is an online service that offers quick and easy conversion between various CAD file formats, including OBJ to STL. It's designed for users who need to convert files without accessing or learning complex software. Key features include: straightforward file conversion, support for multiple CAD formats, and a simple user interface. However, being an online tool, it may not offer the advanced editing or modeling capabilities of dedicated CAD software. Pricing varies based on usage, with options for single conversions or subscription plans. 

What Is OBJ?

OBJ is a standard 3D image file format that stores information about 3D models. The file extension OBJ comes from the name Wavefront OBJect, but its full name is rarely used. It is a plain-text file format, making it easy to read and edit, and it supports both geometry and texture data. The format is widely used for its simplicity and ability to be imported into various 3D graphics applications. Key features of OBJ files include the representation of complex polygonal mesh data, the inclusion of vertex, normal, and texture-coordinate data, and the capability to define material and shading attributes. Its compatibility and simple structure have made it a popular choice for 3D modeling and animation software.

What Is STL?

The STL file format, short for stereolithography, is a widely used file format for 3D printing and additive manufacturing. It represents the surface geometry of a three-dimensional object without any color, texture, or other attributes. STL files contain a series of triangular faces, which collectively describe the outer shell of the 3D model. The simplicity of the format makes it compatible with a broad range of 3D printing software and hardware. It focuses primarily on the physical dimensions and shape of the object. This is why it is the most popular choice for standard 3D printing applications in which the visual appearance is not as important as the geometry.

How To Choose the Best OBJ to STL Converter?

Choosing the best OBJ to STL converter involves considering several key factors to ensure that the conversion process meets your needs including:

1. Compatibility and Support: Ensure the converter supports your operating system (Windows, macOS, Linux) and check for regular updates that improve functionality or fix bugs.
2. Ease of Use: Look for a user-friendly interface that simplifies the conversion process. A good converter should allow you to convert files with just a few clicks without needing to navigate through complex settings.
3. Quality of Conversion: The converter should maintain the integrity of the original OBJ file, including: details, textures, and geometries, without significant loss in quality. Look for options that allow you to adjust resolution or density to manage the balance between detail and file size.
4. Performance and Speed: Consider the conversion speed, especially if you're working with large or multiple files. A converter that utilizes efficient algorithms can save you valuable time.
5. Advanced Features: Depending on your needs, you might require advanced features such as: batch conversion (converting multiple files at once), editing tools (to modify the model before conversion), or customization options for the output STL file.
6. Cost: Determine your budget. While there are free converters available, paid versions often offer more features, better support, and higher conversion quality. Decide whether the additional features in a paid version are worth the investment for your specific needs.
7. Community and Support: A strong user community and responsive customer support can be invaluable, especially if you encounter technical issues or have specific questions about the software.
8. Security: If you're using an online converter, consider the security of your data. Look for platforms that guarantee the privacy of your uploads and downloads.

How Does an OBJ to STL Converter Work?

An OBJ to STL converter transforms 3D models from the OBJ format, which supports complex geometries including textures and colors, into the STL format, primarily used for 3D printing and focusing solely on the model's surface geometry without color or texture. Here's a simplified overview of how the conversion process typically works:

1. The converter loads the OBJ file, reading the data that describes the 3D model's geometry, including: vertices (points in 3D space), edges (lines connecting vertices), and faces (surfaces bounded by edges).
2. The software parses the geometry data from the OBJ file. This involves interpreting the list of vertices and the surfaces defined by these vertices. OBJ files can also contain information about textures and materials; however, this data is ignored during conversion to STL because STL does not support these features.
3. Many OBJ files contain polygons that are not triangles (e.g., quadrilaterals). Since the STL format supports only triangular faces, the converter may need to perform triangulation, dividing polygons into triangles. This step ensures the model's geometry is accurately represented in the STL format.
4. The converter then generates the STL file's geometry, creating a list of the triangular faces that make up the surface of the 3D model. Each triangle is defined by its three vertices and a normal vector indicating the direction in which the triangle faces. The normal vectors are crucial for 3D printing, as they determine the orientation of surfaces.
5. Finally, the converter writes the new STL file, encoding the list of triangles and their normal vectors in either ASCII or binary format, depending on the STL type selected. ASCII STL files are human-readable and contain text describing each triangle, while binary STL files are more compact and store the same information in a format that is readable only by machines.
6. After the STL file is generated, it can be saved to a location specified by the user. The STL file is now ready to be used in 3D printing software, in which it can be sliced into layers for printing.

How Important Is an OBJ to STL Converter in 3D Printing?

An OBJ to STL converter is essential in 3D printing because it transforms detailed models into a print-ready format. Since most 3D printers accept STL files, which only contain geometric data, the converter facilitates the transition from complex designs to a format compatible with 3D printing, ensuring models are accurately prepared for printing.

What Are the Key Features of a Reliable OBJ to STL Converter?

Here are the essential features to look for in a reliable OBJ to STL converter:

1. Accuracy and Integrity of Conversion: The converter should accurately translate the geometry of the OBJ model to STL without losing details or altering the structure of the model. This includes maintaining the integrity of vertices, edges, and faces.
2. Preservation of Mesh Quality: The converter should preserve the quality of the mesh, including the smoothness of curves and the sharpness of edges. It should also allow for mesh repair features like: fixing holes, removing duplicate vertices, and ensuring the mesh is manifold (a requirement for 3D printing).
3. Support for Different STL File Types: The converter should support both ASCII and binary STL file formats, giving users flexibility depending on their needs for file size and compatibility.
4. Preview and Editing Features: Before finalizing the conversion, it’s important to preview the final STL file. Some converters also offer basic editing tools to make last-minute adjustments to the model.
5. User-Friendly Interface: An intuitive interface allows users to easily navigate and use the converter without a steep learning curve.
6. Batch Processing: The ability to convert multiple files at once saves time, particularly for users working with numerous models.
7. Triangulation Support: Since STL supports only triangular faces, the converter should automatically triangulate non-triangular polygons from OBJ files.
8. Error Correction: It should be able to identify and fix common errors in the OBJ file that could affect the printing process, such as non-manifold edges or inverted normals.
9. Configurable Settings: Options to adjust resolution, tolerance levels, and other parameters give users control over the conversion outcome, balancing between detail and file size.
10. Compatibility: The converter should be compatible with different operating systems and integrate well with other software used in the 3D printing workflow.
11. Security and Privacy: If the converter is online, ensure it provides secure uploading and downloading options to protect your models from unauthorized access.

How Does the Accuracy of Geometry Conversion Play a Role in Choosing the Best Converter?

Accuracy in geometry conversion is crucial for choosing an OBJ to STL converter because it ensures the final 3D-printed model closely matches the original design. Converters with high accuracy reduce printing errors and post-processing work.

Is Texture and Color Preservation Important for Conversion Quality?

No. Texture and color preservation are not relevant for OBJ to STL conversions because the STL format does not support these features. STL files are purely geometric and do not contain information about the model's texture or color, focusing solely on shape and structure. If these attributes are important in the project you are working on, it would be better to use an alternative file format that supports them.

How Does the Conversion Speed of an OBJ to STL Converter Impact Its Usability for Different Projects?

Conversion speed is crucial for an OBJ to STL converter's usability, especially for complex or large projects. A fast converter streamlines the workflow and saves time, benefiting time-sensitive and high-volume projects by preventing bottlenecks in the production process.

Is File-Size Limitation a Crucial Factor To Consider When Evaluating Different OBJ to STL Converters?

Yes, file-size limitation is important when selecting OBJ to STL converters. Converters without strict limits can easily handle complex models. This is ideal for detailed 3D printing tasks. On the other hand, converters with strict size limits may require splitting large models into smaller parts before conversion, complicating the workflow and potentially affecting the model's integrity.

Summary

This article presented the best OBJ to STL converters, explained each of them, and discussed their various features. To learn more about OBJ to STL converters, contact a Xometry representative.

Xometry provides a wide range of manufacturing capabilities, including 3D printing and other value-added services for all of your prototyping and production needs. Visit our website to learn more or to request a free, no-obligation quote.

Copyright  and Trademark Notices

1. Tinkercad® and Autodesk Fusion 360® are trademarks of Autodesk, Inc., and/or its subsidiaries and/or affiliates, in the United States.
2. Blender® is a registered trademark of the Blender Foundation in the USA and EU.
3. The FreeCAD® logo is a trademark of the FPA (FreeCAD Project Association), Belgium.
4. MeshLab® is a registered trademark of Consiglio Nazionale Delle Ricerche, Italy.

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