Opening a DCU File

The DCU file type is primarily associated with Delphi.

DCU	File extension: DCU
	File type:	compiled file

What is a DCU file?

DCU files mostly belong to Delphi. DCU files are compiled Delphi units produced when Delphi source code is compiled. They contain binary code that the Delphi linker uses to build the final application.

They store precompiled code from .pas files to speed up compilation.

They are created by Embarcadero’s Delphi compiler.

They are used internally during the build process and are not intended for direct editing.

For more details, visit the Embarcadero website or view the documentation at Embarcadero DocWiki.
FilExt.com note: When working with these files, always refer to the original source (.pas) for any code changes.

How do you open DCU files?

You need a suitable software like Delphi to open a DCU file. Without proper software you will receive a Windows message "How do you want to open this file?" or "Windows cannot open this file" or a similar Mac/iPhone/Android alert. If you cannot open your DCU file correctly, try to right-click or long-press the file. Then click "Open with" and choose an application. You can also display a DCU file directly in the browser:. Just drag the file onto this browser window and drop it.

Online DCU Text Viewer

Choose your .dcu file to analyze

or drag and drop it here

Online File Viewer

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Programs that open and convert DCU files:

Delphi
See the previous paragraphs to learn more about the main application. DCU files are often referred to as Delphi developers because this type of file is primarily created or used by this software.
Delphi (Compiled Unit) by Borland Software Corporation
The format of these files generally changes from one version of Delphi to another so it's often not possible to use a unit compiled with a lower-numbered version of Delphi with a more current version. The identifying characters used for this association are - Hex: DF 00 00 FF.

DCU format details:

If you can determine the file format, the associated program can also be determined. The file format can be deduced from the file extension and the signature. However, different programs can use the same file extension, and file extensions can be assigned incorrectly. Exact knowledge of the format is therefore important in order to solve problems occurring in files. Our analysis of the DCU files produces the following result:

The file type with the extension 'DCU' is used by different programs with different formats. But the following two file formats are common:

25% of all DCU files use the same file format, which have the signature 4D 03 00. These are binary files, so they do not contain words or text. The file size is in the range of 5 KB to 160 KB. This file type is based on cutting-edge technology. The files contain the following words: System, UnicodeString, string, Integer, TObject, TObject.Equals and Boolean8. Files like these are sometimes connected to unit.
20% of all DCU files belong to Delphi 7 Compiled Unit. They consist of unreadable binary data. Most of these files are 3 KB to 90 KB in size. An example of a file name is Unit1.dcu or CommUnit.dcu. Files like these are about comm.

All other DCU files (55%) have no uniform format, the following 9 formats exist: Borland Delphi 6 Library, Delphi 4 Compiled Unit and Delphi 3 Compiled Unit. These files sometimes refer to ufrm, edit or form. If you want to find out which format your DCU file belongs to, just click on the button "Choose your .dcu file to analyze".

Technical Data for DCU File Extension

File classification:

Developer

Identifier:

Hex: DF 00 00 FF (provided by TrID database)

Related files:

pas, dpr, dpk, dproj, res, dfm, dcu2, dcr, dof, bpl, cfg, zip, qr2, dpc, drc

The following listing is compiled from the database produced by the 'Associate This!' program, selected data from the main FILExt database and file extension information submitted by users.

ProgramID: DelphiCompiledUnit
EXEFile: %ProgramFiles%\Borland\Delphi 2.0\Bin\Delphi32.EXE %1

ProgramID: DelphiCompiledUnit
EXEFile: %ProgramFiles%\Borland\Delphi 3\Bin\Delphi32.EXE %1

a dcu compiled file is a special file format and should only be edited and saved with the appropriate software.

How to solve problems with DCU files

Associate the DCU file extension with the correct application.
Update your software that should actually open compiled files. Because only the current version supports the latest DCU file format. Search, therefore, e.g. on the manufacturer website after an available Delphi update.
To make sure that your DCU file is not corrupted or virus-infected, get the file again and scan it with Google's virustotal.com.
Click here to open your .DCU file online - secure, fast, and no downloads needed.