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BREP file format (.brep, .brp)

BREP (native boundary-representation shape format)

What is a BREP file?

BREP is the native geometry format of the open-source CAD kernel that this site and many engineering tools are built on. It stores exact topology and geometry — faces, edges, vertices and the surfaces that carry them — with full fidelity for applications built on that kernel.

  • Lossless for tools built on the same CAD kernel
  • Exact topology and geometry, no tessellation
  • Compact text or binary encoding

Best for: Moving exact geometry between tools built on the same CAD kernel.

View BREP files online

Open .brep / .brp files in the free online BREP viewer — assembly tree, section views and display modes, entirely in your browser.

How to open a BREP file

  1. Open the online BREP viewer. It runs in your browser, so there is no software to install and no account to create.
  2. Drop your .brep or .brp file in. The file is parsed locally and never uploaded. Inspect it with the assembly tree, section views and display modes.
  3. Convert it if you need another format. Press Convert to turn BREP into STL, then download the result straight from your browser.

Convert BREP to other formats

BREP to STLBREP to OBJBREP to PLYBREP to GLBBREP to glTFBREP to 3MFBREP to OFFBREP to USDZ

Frequently asked questions

How do I open a .brep file?

Drop it into the free online BREP viewer on this site — it renders in your browser with an assembly tree and section views, and the file is never uploaded. No software install needed.

Does BREP store units and colors?

Units: model units. Colors/materials: no. Geometry is stored as exact b-rep topology.

How do I convert BREP to STL?

Use the free BREP to STL converter: drop the file, press Convert, download. Everything runs locally in your browser — no upload, no signup.

What is BREP best used for?

Moving exact geometry between tools built on the same CAD kernel.

Does a BREP file include units, colors and a CAD document tree?

No. It stores exact kernel topology and geometry only, while document structure, reliable unit declarations, colors and modelling history live outside the basic BREP file.

Can BREP store animation?

No. BREP is used for open-source cad kernel workflows, and its format does not carry animation tracks.