Convert FreeCAD to STL (Free)
Also converts OBJ, GLB, PLY, USDZ, 3MF, STEP from the same file.
Runs in your browser. No upload, no signup, nothing to install.
Also from Innerscene: Circadian Lab, a free lighting calculator for room illuminance, melanopic EML, and glare.
How to convert FreeCAD to STL
- 1
Open your .fcstd file
Drag it onto the viewer above, or click "Open a FreeCAD File". Files up to 200 MB open directly; the parse runs in a worker so the page stays responsive.
- 2
Pick Stereolithography in the Export menu
Click Export in the toolbar, then STL (.stl).
- 3
Download
The .stl is written in the browser and saved straight to your downloads folder. No queue, no email, no watermark.
What survives the conversion
A file conversion is a translation, and formats do not carry the same things. Here is exactly what moves from FreeCAD into STL, and what does not.
| Geometry | Reduced | FreeCAD stores exact B-rep solids and STL stores triangles, so the surfaces are tessellated. Curved faces become faceted at the display tolerance, which is fine for visualization, printing and clash checking, but not for further parametric CAD work. |
|---|---|---|
| Colors and materials | Dropped | STL has no concept of color or materials, so the material colors in your FreeCAD file are not written. The geometry is unaffected. |
| Layers and structure | Dropped | STL is a single flat body with no layers or named parts. Everything merges into one object. If you need the structure, export to GLB, OBJ, DXF instead. |
| Units and scale | Dropped | STL stores no unit. Coordinates are written in meters, so set the import unit to meters if the destination asks. |
What the STL writer emits: Binary STL, one triangle record per face, positions written verbatim in meters.
The source: FreeCAD document (FCStd) (.fcstd, .fcstd1, .fcbak)
The object tree of a FreeCAD document and the shape FreeCAD stores for every visible object: the OpenCASCADE B-rep, tessellated here, in the object’s saved colour or the colour of each face, at its placement inside its parts and groups, in millimetres. A PartDesign body is drawn once from its finished shape, links are placed where they point, and part files linked from another document are asked for by name. Mesh workbench meshes are drawn too, and shapes without faces (visible sketches, Draft wires and curves) as lines; datums and drawing pages are left out.
The target: Stereolithography (.stl)
The universal 3-D printing mesh. Every slicer and every printing service takes it.
Opens in: Cura, PrusaSlicer, Bambu Studio, Meshmixer, any printing service.
Your file never leaves your computer
Both the FreeCAD parser and the STL writer are JavaScript and WebAssembly running in your own browser tab. There is no upload step, no server-side conversion queue, and no copy of your file anywhere but your machine. That matters for drawings under NDA, for client work, and for anything you would not email to a stranger.
Free to Use, No Signup
There are no accounts and no watermarks on this converter. If it saved you time, the one thing we ask is a mention: a post, a link from your blog or course page, or a reply to someone asking how to open a file.
Share it
Made something reusable? Add it to the Free Parts Library. Writing about it? Copy a link, badge or citation. Send us your post and we’ll feature it with a link to your site.
Hear about new formats
Occasional emails when the viewer learns a new format or gets a new tool.
Frequently asked questions
▶Is this FreeCAD to STL converter free?
Yes. No signup, no watermark, no per-file limit and no paid tier. Innerscene.
▶Is my FreeCAD file uploaded anywhere?
No. The file is read with the browser file API and converted in the same tab. Nothing is sent to a server unless you explicitly click Share, which is a separate, opt-in feature.
▶Will my colors and materials survive the STL export?
STL has no concept of color or materials, so the material colors in your FreeCAD file are not written. The geometry is unaffected.
▶Do layers and named parts carry into the STL file?
STL is a single flat body with no layers or named parts. Everything merges into one object. If you need the structure, export to GLB, OBJ, DXF instead.
▶Will the STL open at the right size?
STL stores no unit. Coordinates are written in meters, so set the import unit to meters if the destination asks.
▶How large a FreeCAD file can I convert?
Up to 200 MB, and the ceiling adapts to how much memory your device reports. The conversion runs on your own hardware, so a desktop with plenty of RAM will handle more than a phone.
▶Can I convert STL back to FreeCAD?
Not here. We read FreeCAD and write STL, but not the reverse. the universal 3D viewer
▶Which browsers does it work in?
Chrome, Edge, Firefox and Safari, on Windows, macOS, Linux, iOS and Android. No plugin and no extension.
Convert FreeCAD to something else
Convert something else to STL
Or start from the universal 3D viewer.