Convert STL to SAT (Free)
Also converts OBJ, GLB, PLY, USDZ, 3MF, WRL 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 STL to SAT
- 1
Open your .stl file
Drag it onto the viewer above, or click "Open an STL File". Files up to 200 MB open directly; the parse runs in a worker so the page stays responsive.
- 2
Pick ACIS SAT in the Export menu
Click Export in the toolbar, then SAT (.sat).
- 3
Download
The .sat 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 STL into SAT, and what does not.
| Geometry | Reduced | The triangles become a faceted B-rep: one planar face per triangle inside a closed shell. CAD reads it as real solid geometry with true units, but the faces stay faceted, they do not become NURBS surfaces. |
|---|---|---|
| Colors and materials | N/A | STL files carry no color, so the SAT comes out in the viewer’s default material. You can color it in the destination application. |
| Units and scale | Kept | SAT stores an explicit unit. STL does not, so the size is taken from how the viewer read the file. Check the scale once on import. |
What the SAT writer emits: ACIS SAT text, save version 7.0, each mesh written as one solid body: a planar face per triangle with shared edges and vertices, so a closed mesh imports as a closed solid. Z up, in millimeters, with the material color on each body. Exact for polyhedral shapes, a faithful tessellation for curved ones.
The source: Stereolithography (.stl)
A single triangle soup. STL stores no color, no units, no parts and no layers, only the surface.
The target: ACIS SAT (.sat)
The ACIS solid format that Revit, SketchUp, Inventor, AutoCAD and most solid modelers import.
Opens in: Revit, SketchUp Pro, AutoCAD, Inventor, Rhino, SpaceClaim, BricsCAD.
Your file never leaves your computer
Both the STL parser and the SAT 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
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Hear about new formats
Occasional emails when the viewer learns a new format or gets a new tool.
Frequently asked questions
▶Is this STL to SAT converter free?
Yes. No signup, no watermark, no per-file limit and no paid tier. Innerscene.
▶Is my STL 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 SAT export?
STL files carry no color, so the SAT comes out in the viewer’s default material. You can color it in the destination application.
▶Will the SAT open at the right size?
SAT stores an explicit unit. STL does not, so the size is taken from how the viewer read the file. Check the scale once on import.
▶How large an STL 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 SAT back to STL?
Yes, the other direction works too. Bear in mind that anything the first conversion dropped is not restored by converting back. SAT → STL
▶Which browsers does it work in?
Chrome, Edge, Firefox and Safari, on Windows, macOS, Linux, iOS and Android. No plugin and no extension.
Convert STL to something else
Convert something else to SAT
Or start from the universal 3D viewer.