README.md

June 5, 2026 · View on GitHub

The Delphi Preview Handler is a preview handler for Windows Vista, 7, 8, and 10 that allows you to read your source code with syntax highlighting without having to open it in an editor.

Features

Supports Windows Vista, 7, 8, and 10 on 32-bit and 64-bit systems.
50+ syntax highlighting themes.
60+ source code extensions supported.
Themes compatible with the Delphi IDE Theme Editor.

This preview handler can render the following file extensions:

Extensions	Description	Preview
.pp, .pas, .lpr, .lpk, .lfm, .inc	Free Pascal/Lazarus files
.pas, .dpr, .dpk, .inc, .dproj, .bdsproj	Delphi files
.c, .cpp, .cc, .h, .hpp, .hh, .cxx, .hxx, .cu	C and C++ source files
.asm	Assembler source files
.e, .ace	Eiffel files	.
.f, .for	Fortran files	.
.java	Java files	.
.csproj, .xaml, .sln, .vcxproj, .vbproj, .jsproj, .appxmanifest	Visual Studio files
.bas, .vb	Visual Basic files	.
.cbl, .cob	COBOL files	.
.cs	C# files
.css	Cascading Stylesheet files
.htm, .html	HTML documents
.js	JavaScript files
.php, .php3, .phtml	PHP files
.vbs	VBScript files	.
.bat, .cmd	MS-DOS batch files	.
.dfm, .xfm	Borland form files	.
.pl, .pm, .cgi	Perl files
.py	Python files
.rb, .rbw	Ruby files
.sh	UNIX shell scripts	.
.sql	SQL files
.iss	Inno Setup scripts
.ini	INI files	.

Important Note about installing a new version

To avoid problems, you must follow these steps when installing or registering a new version of the preview handler.

Close all Windows Explorer instances where the preview handler is active or has been used. Remember that the DLL remains in memory until Windows Explorer is closed.
Unregister the previous version by running the uninstaller located in C:\Program Files (x86)\TheRoadToDelphi\DelphiPreviewHandler or C:\Program Files\TheRoadToDelphi\DelphiPreviewHandler.
If you install the preview handler manually, you must unregister it using UnRegister.bat running as administrator.
Now proceed with the installation of the new version.

Looking for the installer? Check the Release Area.