Native CAD interfaces
Direct support for the CAD formats listed here.
Free 3MF-STL Viewer
Open 3MF and STL files
intuitive & practical 3D without CAD expertise
affordable & universal many 3D/2D interfaces
Modern, easy-to-use CAD viewer
Cost-effective CAD converter for all formats
The 3D-Tool Free Viewer opens 3MF and STL files free of charge without any additional CAD software.
From the Basic Edition onwards, 3D-Tool converts 3MF and STL models to a wide range of formats such as 3D-PDF, OBJ, 3DS, WRL, and PLY.
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Windows support
Compatible with current Windows versions.
What are 3MF and STL files?
- These formats represent a 3D model by breaking its surface into thousands of triangles. The triangulation parameters determine the number of triangles, representation accuracy, and file size. This type of 3D data is called MESH data, faceted data, or visualization data.
- STL files (stereolithography) contain only faceted 3D models for manufacturing with additive processes in 3D printing or rapid prototyping. Surface description in STL format has been an industry standard since 1987.
- 3MF files (3D Manufacturing Format) contain a range of additional information alongside the 3D model, including assemblies, units, colors, textures, and printer profiles. 3MF is an open-source format from the 3MF Consortium and is based on XML.
STL versions
ASCII STL files use simple character encoding (text, numeric values) to store triangulated 3D models. For complex models and accurate representations, ASCII files quickly become very large. ASCII is the oldest STL format, but today there is usually no reason to create ASCII files except for special or older software.
Binary STL files use binary encoding (bits, bytes) to store triangulated 3D models. Binary files are significantly smaller than ASCII files. After each triangle, the STL standard leaves an unspecified 2-byte sequence as a spacer. Some software uses these 2 bytes to encode information such as color, but this is not implemented consistently.
3MF - specification and extensions
The 3MF specification was designed by the 3MF Consortium to be open and extensible. The 3MF Core includes several extensions for 3D printing files:
- Materials and Properties extension enables materials and properties to be stored in 3D printing files.
- Production extension enables production information to be stored.
- Beam Lattice extension enables more efficient storage of uniform lattice structures (Lattice Structures).
- Slice extension enables slice information to be stored.
- Security extension enables implementation of digital rights management (DRM).
- Volume extension enables volume information to be stored.
How do I open STL and 3MF files?
All 3D printing software and rapid prototyping software should support STL files. The newer 3MF format is also already widely used and, like STL, can be read by some free online viewers and the Windows 3D-Builder.
The 3D-Tool Viewer, as well as the 3D-Tool Free Viewer, which is free for private and commercial use, open STL and 3MF files. In contrast to simple 3MF and STL readers, 3D-Tool offers extensive measuring tools in all versions, including volume and weight calculation, the calculation of the smallest surrounding box and wall thickness analysis.
How do I convert STL and 3MF files?
Conversion between triangulated formats is relatively simple. Even the Basic version of the 3D-Tool CAD Viewer supports the import and export of common Mesh formats, including converting 3MF to STL, 3MF to OBJ and 3MF to 3D-PDF.
On the Internet you often find the question of how to convert STL to STEP or, in general, any triangulated formats such as STL, 3MF, 3DS, PLY into an exact 3D CAD format. Automatic conversion is not possible. Using special software, the many triangles of the model must be converted more or less manually into exact surfaces (reverse engineering).
Test the STL viewer and 3MF viewer for free
3D-Tool is an intuitive CAD Viewer available in one free and three commercial license variants, always with professional information and measurement functions.
- The 3D-Tool Free Viewer opens STL and 3MF, but cannot export 3D formats. Simply download it from our website and use it.
- 3D-Tool Basic opens 3D visualization formats such as STL, 3DS, OBJ, PLY, and VRML.
- 3D-Tool Advanced also opens the 3D exchange formats STEP, IGES, VDA, SAT, and Parasolid.
- 3D-Tool Premium, including the 3D-NativeCAD Converter, opens and converts native 3D models from CATIA, Siemens NX, Creo, Inventor, Solid Edge, SolidWorks, Rhino, and AutoCAD, as well as the 3D exchange formats STEP, IGES, VDA, SAT, Parasolid, and JT.
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