Supported files. Clear boundaries.
This is a tool for 3MF triangle geometry. A file ending in .3mf may also contain slicer settings, special geometry, or only toolpaths. The contents determine what can be converted.
The supported geometry subset
- Standard triangle meshes with finite coordinates and valid indices.
- Nested mesh components and repeated printable build instances.
- Translation, rotation, scaling and mirrored placements.
- Production extension references between model parts inside the same package, with consistent source units.
- All six core units, normalized to millimeters.
- Core and material appearance information may be read, but is discarded from geometry-only STL.
Models are opened using self-hosted lib3mf 2.5.0 after bounded ZIP/XML checks. See the actual slicer compatibility matrix and tests. Files with mixed units across model parts are rejected with an explanation. A successful sample does not imply support for every project from the same application.
Resource limits
| Resource | Current ceiling |
|---|---|
| Input file | 50 MiB |
| Total expanded archive data | 200 MiB, counted during decompression |
| Expanded triangles | 1,000,000, including repeated instances |
| ZIP entries | 10,000 |
| Component hierarchy | 64 levels |
| Coordinate precision range | ±10,000 mm on each output axis; source-reader rounding estimate no greater than 0.001 mm |
These are rejection thresholds, not a promise that every file below them will run smoothly. Device memory, coordinate data and preview complexity affect practical capacity. Start with a smaller file on a phone. You can cancel a running operation.
Why a file may be rejected
Binary STL uses 32-bit coordinates. Small details can disappear when a model is placed extremely far from the origin. The tool rejects output coordinates outside the range above and source coordinates or transforms that exceed its reader-rounding screen after placement and unit conversion. Move the model near the origin or simplify transforms in its source application and re-export it; this tool never silently recenters it. These are conservative safeguards, not a guaranteed final error bound for every model. See the measured precision tests.
| Error | Meaning | Next step |
|---|---|---|
| BAD_ARCHIVE | Damaged, encrypted, unsafe, or incomplete package. External relationships are not read. | Re-export an unencrypted mesh 3MF from its source application. |
| BAD_XML | Invalid XML, unsupported encoding, or DTD/entity content. | Re-save using a supported 3MF exporter. |
| NO_MESH | No printable build geometry; may be a G-code-only project. | Find the original design or mesh project. Toolpaths cannot restore the original surface here. |
| UNSUPPORTED_EXTENSION | A required or geometry-bearing extension is not supported. | Open the file in its source application and export a standard mesh. |
| UNSUPPORTED_GEOMETRY | Non-model object type, beams, slices, or other special geometry. | Export the intended printable surface as a mesh. |
| INVALID_GEOMETRY | Invalid indices or numbers, empty mesh, missing objects, circular references, or coordinates outside the precision range. | Inspect the original project. For the precision-range error, move the model near the origin in its source application and re-export. |
| RESOURCE_LIMIT | A size, count, or nesting threshold was reached. | Export fewer objects or simplify the source geometry in your modeling application. |
| ENGINE_ERROR | The local engine could not load or could not interpret the package consistently. | Reload, try the small sample, and check the source application’s export options. |
Warnings do not mean automatic repair
A degenerate triangle has zero area. If retained by the reader, we count and report it. We do not remove or repair it. Watertightness, self-intersections and printability are explicitly marked “not tested.” The tool does not reconstruct a mesh from G-code, fuse overlapping surfaces or preserve project editability.
If the 3D preview is unavailable
The canvas requires WebGL. If your browser or graphics driver cannot provide it, you can still inspect text dimensions and download when the conversion engine succeeds. Parsing also requires JavaScript, WebAssembly and Web Workers.
On a download-restricted mobile browser, use the download-ready link again and check your browser’s Downloads or Files location. Keep the page open until the file has saved.
Open the 3MF converter →Format references: 3MF Consortium specifications · lib3mf 2.5.0 release. Product behavior is documented in our test method and results.