DGN File

What are DGN files and how to open them

Are you having problems opening a DGN file or are you simply curious about its contents? We're here to explain the properties of these files and provide you with software that can open or handle your DGN files.

What is a DGN file?

DGN files have multiple uses, and Bentley MicroStation CAD drawing is one of them. Read more about the other uses further down the page.

Bentley MicroStation CAD drawing

Files that use the .dgn file extension are most commonly associated with the MicroStation construction design software application. The DGN files that are used by this software contain 2D or 3D drawings that are based on the Intergraph Standard File Format or, in some cases, the V8 DGN standard.

How to open DGN files

We have identified six DGN openers that are compatible with this specific type of DGN file.

Programs that open Bentley MicroStation CAD drawing files

Last updated: October 27, 2026

All known file formats using extension .DGN

While Bentley MicroStation CAD drawing is a popular type of DGN-file, we know of 2 different uses of the .DGN file extension. Different software may use files with the same extension for different types of data.

PC-Dragon Cartridge Image

The PC-Dragon Cartridge Image format is a binary image of a cartridge meant for the Dragon, Dragon 32/64 or Tandy CoCo machines, as emulated by Paul Burgin's PC-Dragon emulator. These files store the contents of a ROM cartridge - code, data or firmware that would normally be physically plugged into the cartridge port. It is used when dumping a real cartridge's contents for use in emulation or when converting ROMs for PC-Dragon.

Creation of these images is done by the Dragon Convert utility included with PC-Dragon. This tool takes existing data (often via copied cassette images in .CAS format) and writes it out in cartridge-image form (that is, this format) for use as ROM cartridges. Emulators such as XRoar recognize these images as "firmware ROM images" or "cartridge images", similar to files with extension .ROM, and load them directly into cartridge memory space.

Files begin with a signature byte of 0xA1 at offset 0, and contain the byte sequence 0x02 00 00 C0 00 C0 00 at offset 9. These signatures distinguish this specific cartridge image format.

While we have not verified the apps ourselves yet, our users have suggested ten different DGN openers which you will find listed below.

Various apps that use files with this extension

These apps are known to open certain types of DGN files. Remember, different programs may use DGN files for different purposes, so you may need to try out a few of them to be able to open your specific file.

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