STL File Info: Binary or ASCII, Triangle Count, Header
Inspect what is inside an STL file: encoding, header text, triangle count, bounding box and whether the mesh is closed. Handy before sending a file to a print service.
How it works
- 1Drop the STL
Header and encoding are read from the raw bytes.
- 2Read the report
Encoding, solid name, triangle count, size consistency and watertightness.
- 3Act on it
Use the linked tools to convert the encoding, scale or repair.
Details
A binary STL begins with an 80-byte header that exporters fill with their name and sometimes the unit or color information (Materialise Magics and SolidWorks do this). The 4-byte count that follows must match the file length: 84 + 50 × triangles. A mismatch means the file was padded, truncated or is actually ASCII.
Accepted formats: STL
Frequently asked questions
More STL tools
- Get the Dimensions of an STL File
Drop an STL (or any 3D file) to read its exact width, depth and height, bounding box, volume, surface area and triangle count. Runs in your browser, nothing is uploaded.
- Reduce STL File Size (Simplify Mesh)
Cut the triangle count of an STL file by a chosen percentage while keeping the shape. Useful for oversized 3D scans, slow slicers and upload limits. Runs locally in your browser.
- Convert STL ASCII to Binary (and back)
Convert a text (ASCII) STL into the compact binary STL that slicers load faster, or the other way round for inspection. Binary files are typically 4–5× smaller.
- Scale / Resize an STL File
Resize a 3D model by a factor, to an exact target dimension, or fix a model that came out 25.4× too small or too big because of inch/millimeter confusion.
- Repair an STL File
Weld duplicate vertices, remove degenerate triangles, recompute normals and get a report of open and non-manifold edges before you slice. Basic repair for common export problems.