STL ASCII / Binary Converter
Convert STL files between ASCII and binary format
Drop an STL fileTap to choose an STL file
or click to browseor tap to choose
Convert between ASCII and binary STL, auto-detects the current format. Drop several files to get one ZIP.
Large files (over 50 MB) may take longer or run out of browser memory
About STL ASCII / Binary Converter
Converts an STL file between its ASCII (human-readable text) and binary (compact) representations, auto-detecting which format your file is currently in.
Upload your STL file (or several at once), and convert it to either ASCII or binary format. A file that is not a real STL is flagged straight away and can't be converted. One file downloads as an .stl; several download as one ZIP.
This converts the geometry only: the 80-byte header text and any per-triangle colour bytes are not carried over, and the face normals are recalculated from the triangles. Binary STL files are significantly smaller than the equivalent ASCII version for the same geometry — if file size matters for storage or transfer, binary is almost always the better choice.
Watch: STL ASCII / Binary Converter in Action
- Should I use ASCII or binary STL format?
- Binary STL files are significantly smaller than the equivalent ASCII version for the same geometry — if file size matters for storage or transfer, binary is almost always the better choice.
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