Format conversion/Mesh ↔ mesh
STL to OBJ converter (local)
Convert binary or ASCII STL to OBJ entirely in your browser. Binary STL is read in 4 MiB triangle-aligned slices; the Worker welds shared vertices and writes an indexed OBJ for immediate local download.
Conversion
No uploadReady to convert
The input is streamed in 4 MiB slices; the output is assembled in the Worker and downloaded locally.
- Formats
- STL → OBJ
- Worker
- in your browser
Drop an STL here
Binary STL streams in 4 MiB slices; ASCII STL streams line by line.
Choose a fileMax file size: 500 MB · No upload
No upload · File.slice() → Worker → chunked OBJ output.
How it works
- 1
Drop one binary or ASCII STL file.
- 2
The Worker streams binary STL in 4 MiB slices and ASCII STL line by line, welds shared vertices, and computes geometry statistics.
- 3
The OBJ writer emits vertices and faces in chunks with one default group. Source units are preserved.
- 4
Download the OBJ locally. No upload is performed.
What the numbers mean
STL is unitless. The converter preserves the source coordinates without rescaling, so confirm the intended unit before printing or importing; a 25.4× error is the classic 3D-printing failure.
STL has no material names. OBJ output uses a single default group and no MTL file; add materials in your modeling tool if needed.
Printing notes
- OBJ is usually smaller than binary STL for the same triangle count because vertices are shared instead of repeated per face.
- Check that your target slicer interprets the OBJ units and up-axis consistently with the original STL.
- Keep the original STL until the converted mesh is verified.
Questions
References
- · Wavefront OBJ specification
- · ISO/ASTM 52900