Convert STEP to DXF (Free)
Also converts STL, OBJ, GLB, PLY, USDZ, 3MF 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 STEP to DXF
- 1
Open your .step file
Drag it onto the viewer above, or click "Open a STEP File". Files up to 200 MB open directly; the parse runs in a worker so the page stays responsive.
- 2
Pick AutoCAD DXF R12 in the Export menu
Click Export in the toolbar, then DXF (.dxf).
- 3
Download
The .dxf 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 STEP into DXF, and what does not.
| Geometry | Reduced | STEP stores exact B-rep solids and DXF 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 | Reduced | STEP can hold material colors and DXF holds one color per object, so materials are flattened to that. |
| Layers and structure | Kept | Layers survive as real layers in the DXF file, so you can still isolate and toggle them. |
| Units and scale | Kept | DXF stores an explicit unit, so the model opens at true size without rescaling. |
What the DXF writer emits: ASCII R12 DXF, which opens in every AutoCAD release back to 1992. A 3-D model writes every triangle as a 3DFACE, in millimeters and Z-up. A drawing writes LINE, POLYLINE, ARC, CIRCLE, TEXT and SOLID in the drawing’s own units, on layers named after the source layers, with color as the nearest ACI palette index.
The source: STEP (ISO 10303) (.step, .stp)
The B-rep solids and surfaces of the assembly, tessellated to display meshes, with the product tree and real units.
The target: AutoCAD DXF R12 (.dxf)
The CAD interchange format that opens in everything, back to AutoCAD releases from 1992.
Opens in: AutoCAD, BricsCAD, DraftSight, LibreCAD, QCAD, Rhino, laser and CNC software.
Your file never leaves your computer
Both the STEP parser and the DXF 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.
Frequently asked questions
▶Is this STEP to DXF converter free?
Yes. No signup, no watermark, no per-file limit and no paid tier. Innerscene.
▶Is my STEP 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 DXF export?
STEP can hold material colors and DXF holds one color per object, so materials are flattened to that.
▶Do layers and named parts carry into the DXF file?
Layers survive as real layers in the DXF file, so you can still isolate and toggle them.
▶Will the DXF open at the right size?
DXF stores an explicit unit, so the model opens at true size without rescaling.
▶How large a STEP 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 DXF back to STEP?
Not here. We read STEP and write DXF, 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 STEP to something else
Convert something else to DXF
Or start from the universal 3D viewer.