# 3MF to STL

> Browser-based 3MF, STEP, STP, IGES, IGS, OBJ, STL, GLB, PLY, and FBX conversion tools for privacy-first 3D workflows.

3MF to STL helps users convert `.3mf`, `.step`, `.stp`, `.iges`, `.igs`, `.obj`, `.stl`, `.glb`, `.ply`, and `.fbx` files locally in the browser. STEP, STP, IGES, and IGS conversion uses adjustable tessellation (turning exact CAD surfaces into triangles), while OBJ, STL, GLB, PLY, and FBX tools convert mesh geometry. The most important product behavior is that model files remain on the user's device.

Every converter pauses after parsing to show an input preview with mesh count, triangle count, and dimensions. Users confirm the source and output unit, up axis, and keep, merge, or split behavior before conversion. The exact direct-download Blob or ZIP is then reparsed with the target parser; only verified output receives an output preview and enabled download button.

## Primary Pages

- [AI Overview](https://3mftostl.online/ai-overview.md): Single-file overview of the site, converter behavior, intended audience, and important constraints.
- [Homepage markdown](https://3mftostl.online/index.html.md): Main converter overview, workflow, capabilities, and FAQ.
- [3MF vs STL markdown](https://3mftostl.online/3mf-vs-stl.md): Comparison of format trade-offs, compatibility, and when export makes sense.
- [How to Export 3MF to STL markdown](https://3mftostl.online/how-to-export-3mf-to-stl.md): Practical step-by-step export workflow.
- [3MF to STL Online Free markdown](https://3mftostl.online/3mf-to-stl-online-free.md): Browser conversion guidance focused on privacy, speed, and free usage.
- [STEP to STL](https://3mftostl.online/step-to-stl): Local CAD-to-mesh converter for `.step` files.
- [STP to STL](https://3mftostl.online/stp-to-stl): Local CAD-to-mesh converter for `.stp` files.
- [IGES to STL](https://www.3mftostl.online/iges-to-stl): Local IGES surface-to-mesh converter with preview, coordinate controls, and output validation.
- [IGS to STL](https://www.3mftostl.online/igs-to-stl): Local converter for the legacy `.igs` extension.
- [OBJ to STL](https://www.3mftostl.online/obj-to-stl): Local OBJ mesh to STL converter.
- [STL to OBJ](https://www.3mftostl.online/stl-to-obj): Local STL mesh to OBJ converter.
- [GLB to STL](https://www.3mftostl.online/glb-to-stl): Local binary glTF scene mesh to STL converter.

## Policies and Support

- [Privacy Policy markdown](https://3mftostl.online/privacy.md): Local processing and analytics notes.
- [Terms of Use markdown](https://3mftostl.online/terms.md): Scope and warranty limitations.
- [Contact markdown](https://3mftostl.online/contact.md): Support contact details.

## Optional

- [llms-full.txt](https://3mftostl.online/llms-full.txt): Expanded AI-readable overview with more detail about the converter, pages, and usage constraints.

## Scan and scene mesh converters

- [PLY to STL](https://www.3mftostl.online/ply-to-stl): Local ASCII and binary PLY surface conversion. Triangles and convex quads only; point clouds and Gaussian splats require surface reconstruction. Scan colors and custom attributes are lost. Confirm unit and up axis. Standard PLY produces one STL, without inferred part splitting.
- [FBX to STL](https://www.3mftostl.online/fbx-to-stl): Local static FBX mesh conversion with declared units, up axis and baked object transforms. Merge meshes or split them into a ZIP of STL files. Bake rigs, morph targets and animations and remove texture/media assets before upload. Scene hierarchy, materials, colors, cameras and lights are lost.

Both tools show the input geometry and an output preview rebuilt by reparsing the exact download bytes. Mesh count, triangle count, finite coordinates, placement and dimensions must match before download. STL is unitless. Neither converter repairs holes, unions overlapping surfaces or reconstructs absent geometry.


## OBJ extraction from web scenes and CAD

- [GLB to OBJ](https://www.3mftostl.online/glb-to-obj): Extract static GLB default-scene meshes with available normals and the first UV set. Bake node transforms, choose output unit and up axis, and keep named objects, merge, or split into a ZIP. PBR materials, texture images, vertex colors, extra UV sets and nested hierarchy are lost; no MTL file is generated. Bake rigs, morph targets and animation first. Unsupported compression, required extensions and external companion resources are rejected.
- [STEP / STP to OBJ](https://www.3mftostl.online/step-to-obj): Accept both .step and .stp files on one page. Tessellate CAD solids and surfaces with Draft, Balanced or Fine quality. Coordinates are normalized to millimeters; confirm the guessed source up axis and choose output unit and orientation. Keep detected parts as flat OBJ objects, merge, or split into a ZIP. Exact CAD surfaces, B-Rep topology, colors, engineering tolerances, PMI and assembly hierarchy are lost. UVs, textures and MTL files are not reconstructed.

Both workflows run locally, show parsed input geometry, and independently reparse the exact OBJ download or every OBJ entry in the generated ZIP. Download is enabled only after mesh count, triangle count, finite geometry, placement and dimensions match the conversion plan. OBJ stores no unit declaration. Import using the selected coordinate unit. Conversion does not repair meshes or perform Boolean unions. STEP output verification compares with the selected tessellation, not exact analytic CAD surfaces.

- [3MF to OBJ](https://www.3mftostl.online/3mf-to-obj): Extract supported core 3MF build items as named OBJ objects, merge into one mesh or split into a ZIP. Bake component and build placement, correct mirrored faces, and convert declared units and Z-up once. Texture UVs, colors, materials, images, manufacturing metadata and slicer settings are omitted; no MTL is generated. Keep the original print project. Required extensions, invalid geometry and external dependencies are rejected.
- [IGES / IGS to OBJ](https://www.3mftostl.online/iges-to-obj): Tessellate supported .iges and .igs surface or solid faces at Draft, Balanced or Fine quality. Keep, merge or split detected parts. The CAD engine normalizes units to millimeters; confirm the guessed up axis and choose output coordinates. Exact CAD topology, curves, NURBS, tolerances, drawing data and colors are lost. No surface healing, texture unwrap or MTL output is provided. Resolve external references before upload.
- [PLY to OBJ](https://www.3mftostl.online/ply-to-obj): Convert ASCII or binary little/big-endian PLY 1.0 surface meshes. Retain authored normals and common vertex UV pairs (u/v, s/t, texture_u/texture_v) or face texcoord lists; triangulate planar convex quads. Scan colors, alpha, custom scanner attributes and images are omitted, with no MTL output. PLY is one mesh; merge and split are unavailable. Confirm unitless source scale and guessed up axis. Point clouds, Gaussian splats and unsupported polygons require preprocessing.

These OBJ routes process files locally, show parsed input and independently reparsed output previews, and validate the exact OBJ or ZIP download against mesh count, triangles, finite geometry, dimensions and placement. OBJ stores no physical unit: import using the selected output unit. Download remains unavailable if verification fails.