Open an Open CASCADE BREP file online
BREP and BRP files store Open CASCADE boundary-representation solids and surfaces. Tessellate supported exact CAD geometry locally, then orbit and inspect the resulting 3D mesh without uploading the model.
Interactive viewer — This format is parsed and rendered in the browser.
Drop a BREP file to open it
or click to choose — everything stays on your device
Choose file🔒 100% private — files never leave your browser
Or turn BREP into an image — snapshot the preview, add arrows or notes, and download a PNG.
What is a BREP file?
BREP and BRP files store Open CASCADE boundary-representation solids and surfaces. Tessellate supported exact CAD geometry locally, then orbit and inspect the resulting 3D mesh without uploading the model. The .BREP extension identifies a Open CASCADE boundary representation file, which is served with the application/octet-stream media type. You can open it here instantly — drop the file into the box above and it renders in your browser. Nothing is uploaded.
Boundary representation describes a solid through connected faces, edges and vertices rather than only display triangles. Open CASCADE uses BREP as a native persistence format for precise curves and surfaces. The optional WebAssembly engine tessellates supported shapes in browser memory so they can be reviewed interactively.
Besides this free online viewer, you can open Open CASCADE BREP files in desktop apps such as FreeCAD, Open CASCADE Draw, CAD Assistant — but here all you need is a web browser.
Quick facts
| Format | Open CASCADE BREP — Open CASCADE boundary representation |
|---|---|
| File extensions | .brep .brp |
| MIME type | application/octet-stream |
| Developer | Open CASCADE |
| Category | 3D, CAD & GIS |
| Also opens in | FreeCAD, Open CASCADE Draw, CAD Assistant |
Common uses
- Check whether an Open CASCADE export contains visible solids
- Review part orientation and overall shape before exchange
- Preview a FreeCAD or CAD Assistant BREP on a device without desktop CAD
What this browser preview can and cannot show
The interactive result is a tessellated preview, not the exact mathematical model. Feature history, constraints, names, colours, tolerances and application-specific attributes may be missing. This viewer cannot repair or edit the BREP.
Tips for a reliable preview
- Use STEP when exchanging with software that does not support Open CASCADE BREP
- Keep the original file for tolerance-sensitive work
- Allow extra loading time for complex faces and large assemblies
How to open a BREP file online
- Click Choose file above, or drag your BREP file onto the box.
- The right viewer loads automatically and renders your file.
- Read, scroll or page through it. To open a different file, choose Open another file.
100% private — files never leave your browser.
Libraries used to render BREP in the browser
This viewer is built entirely with open-source JavaScript that runs in your browser:
Frequently asked questions
What is a .BREP file?
A .BREP file is a Open CASCADE boundary representation, identified by the application/octet-stream media type. You can open and read it instantly in the viewer above without installing anything.
What programs open BREP files?
On the desktop, BREP files typically open in FreeCAD, Open CASCADE Draw, CAD Assistant. Online, this page opens them in any modern browser — nothing to download.
How do I convert BREP to an image?
Use Snapshot to capture the BREP preview, optionally add arrows, text or highlights, then download it as a PNG image.
Is the displayed mesh as precise as the original BREP?
No. Curves and surfaces are tessellated for screen display. Use a CAD kernel when exact measurements or manufacturing decisions are required.
Is it safe to open my BREP file here?
Yes. The file is read and rendered entirely by JavaScript inside your own browser. It is never uploaded to a server, so nothing leaves your device.
Do I need to install anything to view a BREP file?
No. There is nothing to install and no account to create. Open the page, drop your file, and it displays instantly.
Does it work on my phone or iPad?
Yes. The viewer is fully responsive and works in modern mobile and tablet browsers such as Safari and Chrome.
Is there a file size limit?
There is no hard limit, but very large files depend on your device’s memory. Big files are processed in the background so the page stays responsive.