Add your OFF file
Drop one or more .off files onto the converter above, or browse for them. They load into browser memory only — nothing is uploaded, so there is no size-based pricing and no server queue.
OFF to STL
Converting a .off mesh to .stl rewrites the same triangles for a different toolchain. Free, private, and validated — the file never leaves your browser.
Private for supported formats — processed in your browser
Runs on your deviceConvert supported files
Drop OFF files here
Batch files can each use a different output. Nothing uploads for local conversions.
Working inputs include camera RAW, browser-local audio/video, PDF, CBZ/CBR comics, office documents, ebooks, markup, 3D models, structured text, images, and archives.About converting Object File Format mesh to STL mesh
Converting a .off mesh to .stl rewrites the same triangles for a different toolchain. An .off file is about the simplest polygon mesh format that exists: the word OFF, a line giving the vertex, face and edge counts, then the vertex coordinates and then the faces, each written as a vertex count followed by that many indices. There are no materials, no transforms and no scene graph — only geometry.
STL is the original 3D-printing file format: a .stl file reduces a solid model to a shell of triangles, each defined by three vertices and a facet normal. Its brutal simplicity — no units, no color, no structure — made it the universal least common denominator for sending shapes to a printer. For this route the practical draw is understood by every slicer, printer, CAD package, and mesh tool without exception and simple to generate and parse — balanced against missing units cause real-world scale errors between metric and imperial toolchains, which is worth knowing before you commit a large batch.
Why convert OFF to STL?
The practical trigger for this conversion is usually a mismatch: with .off, no materials, textures, normals or scene structure in the base variant. Switching to .stl buys you understood by every slicer, printer, CAD package, and mesh tool without exception, which is why it is the better fit for sending models to slicers for FDM, SLA, and SLS printing. Because the conversion runs locally, trying it costs nothing but a few seconds of compute on your own machine.
OFF vs STL at a glance
| Aspect | Object File Format mesh (.off) | STL mesh (.stl) |
|---|---|---|
| Format type | Lossless — every pixel or sample is preserved exactly | Vector — resolution-independent geometry instead of pixels |
| How it stores data | plain ASCII. The header line is literally OFF, optionally COFF or NOFF when colours or normals are present | binary STL stores an 80-byte header, a 32-bit triangle count, and fifty bytes per facet; the older ASCII form spells out solid, facet, and vertex keywords |
| Strongest at | computational-geometry and mesh-processing research, where the format's simplicity is the point | sending models to slicers for FDM, SLA, and SLS printing |
| Weak spot | no materials, textures, normals or scene structure in the base variant | missing units cause real-world scale errors between metric and imperial toolchains |
| Metadata | none. OFF carries geometry only — no names, no units, no authorship | essentially none — the binary header offers 80 free-form bytes and the ASCII solid name a single token, neither standardized for metadata |
Pick STL as the output
Select .stl in the output menu next to each file. The menu only offers targets this engine can genuinely produce, so if STL is selectable, the route is real and validated.
Convert on your device
Press Convert. The mesh is parsed, retriangulated where needed, and rewritten locally with full validation.
Verify and download
Each result is signature-checked before the download unlocks, so a failed encode can never masquerade as a valid STL file. Outputs keep the original filename with the .stl extension.
OFF to STL questions, answered
Will converting OFF to STL lose quality?
Since off is lossless-oriented and stl is vector-oriented, the conversion preserves the source content exactly as stored; no additional compression pass is applied beyond what .stl itself requires.
Is it private to convert OFF files here?
Yes — the .off file is processed inside your browser tab and never uploaded. The mesh is parsed, retriangulated where needed, and rewritten locally with full validation. Close the tab and the file is gone from memory.
Where will the STL file work?
Support is as close to universal as 3D formats get: every slicer (PrusaSlicer, Cura, Bambu Studio), every CAD package, and mesh tools from Blender to MeshLab read and write .stl, and Windows and macOS both preview it natively. Its weaknesses are functional rather than compatibility-related — which is exactly why 3MF was designed to replace it.
Will the STL file be bigger or smaller than my OFF?
It depends on the content: binary STL stores an 80-byte header, a 32-bit triangle count, and fifty bytes per facet; the older ASCII form spells out solid, facet, and vertex keywords. Convert one representative file first and compare before batch-processing a large set.
What happens to the metadata in my OFF file?
In .off, none. OFF carries geometry only — no names, no units, no authorship. Re-encoding through the browser pipeline does not carry embedded metadata into the output, which doubles as a privacy scrub — check the exported file if you specifically need tags preserved.