DFN file format description

Many people share .dfn files without attaching instructions on how to use it. Yet it isn’t evident for everyone which program a .dfn file can be edited, converted or printed with. On this page, we try to provide assistance for handling .dfn files.

1 filename extension(s) found in our database.

.dfn - Delphi Definition File

The DFN development files are related to Embarcadero Delphi. The DFN file is a Delphi Definition File. Embarcadero Delphi is an integrated development environment (IDE) for console, desktop graphical, web, and mobile applications.

Embarcadero Delphi
Development files
- / -
Delphi Definition File related extensions:
Stata Batch File
DS Game Maker Action Description
Yukes 3D Object
wxBasic Source Code
Dart Compiled Binary
JRockit Flight Recorder Template

Naturally, other applications may also use the .dfn file extension. Even harmful programs can create .dfn files. Be especially cautious with .dfn files coming from an unknown source!

Can't open a .dfn file?

When you double-click a file to open it, Windows examines the filename extension. If Windows recognizes the filename extension, it opens the file in the program that is associated with that filename extension. When Windows does not recognize a filename extension, you receive the following message:

Windows can't open this file:


To open this file, Windows needs to know what program you want to use to open it. Windows can go online to look it up automatically, or you can manually select one from a list of programs that are installed on your computer.

To avoid this error, you need to set the file association correctly.

The .dfn file extension is often given incorrectly!

According to the searches on our site, these misspellings were the most common in the past year:

cfn, dbn, dcn, den, df, dfb, dfg, dfh, dfm, dgn, dn, dnf, drn, dtn, dvn

Is it possible that the filename extension is misspelled?

Similar file extensions in our database:

Autodesk Land Desktop Drawing Specific Settings Data
Calamus Font Data
RoboForm Safenote File
Data Flask Grid
Kissock EModel Data Variables
Paradox Table Filter

Operating systems

DataTypes.net currently supports the following operating systems:

Windows XP/Vista, Windows 7/8/10, Windows 11, CentOS, Debian GNU/Linux, Ubuntu Linux, FreeBSD, macOS, Mac OS X, iOS, Android

If you find the information on this page useful, please feel free to link to this page.


If you have useful information about the .dfn file format, then write to us!

DataTypes.net >> DFN file