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File Extensions

Browse file extensions by category or letter. Learn what each file type is used for and find software that can open, view, edit, or convert it.

159
Indexed file extensions

Find the right information for any file extension

Use this directory to look up file formats, understand what files are used for, and find compatible applications for Windows, macOS, Linux, mobile, and online tools.

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159 extensions
Programming Clear all
.STYL

Stylus Stylesheet

Stylus is a preprocessor scripting language that is compiled into Cascading Style Sheets (CSS). It is designed to be a concise, flexib…

Programming
.HPP

C++ Header File

An HPP file is a header file specifically associated with the C++ programming language. It serves as a container for declarations of c…

Programming
.SASS

Syntactically Awesome Style Sheets

Sass (Syntactically Awesome Style Sheets) is a preprocessor scripting language that is compiled or interpreted into Cascading Style Sh…

Programming
.LSP

Lisp Source Code File

An LSP file is a source code file written in the Lisp programming language, which is one of the oldest and most influential high-level…

Programming
.XHTML

eXtensible HyperText Markup Language

XHTML (eXtensible HyperText Markup Language) is a markup language that is a reformulation of HTML 4 as an XML application. This means…

Programming
.SRC

Source Code File

A file with the .src extension is a generic source code file containing human-readable instructions written in a programming or script…

Programming
.CPP

C++ Source Code File

A .cpp file is a source code file written in the C++ programming language, which is a high-level, general-purpose language that evolve…

Programming
.UNITYPACKAGE

Unity Package File

A Unity Package file, typically with the '.unitypackage' extension, is a proprietary archive format used by the Unity game engine. It…

Programming
.VCXPROJ

Visual C++ Project

A VCXPROJ file is a project file used by Microsoft Visual Studio to store information and build settings for a C++ programming project…

Programming
.VLX

AutoCAD Compiled Visual LISP File

The VLX file extension is associated with AutoCAD, a professional computer-aided design (CAD) software developed by Autodesk. It repre…

Programming
.ASM

Assembly Language Source Code File

An ASM file is a source code file written in Assembly language, which is a low-level programming language closely related to machine c…

Programming
.HXX

C++ Header File

A file with the .hxx extension is a header file used primarily in C++ programming. It typically contains declarations of classes, func…

Programming
.SCM

Scheme Source Code File

The .scm file extension is primarily associated with source code files written in the Scheme programming language, which is a minimali…

Programming
.CSPROJ

C# Project File

A .csproj file is a project file used by the Microsoft .NET framework to store information about a C# software project. It is an XML-f…

Programming
.PRG

Program File

The .prg file extension is a versatile suffix primarily used to denote program files or source code scripts across several distinct co…

Programming
.NIB

Interface Builder User Interface File

A NIB file is a resource file used in macOS and iOS development to store user interface designs. The acronym stands for NeXT Interface…

Programming
.HH

C++ Header File

A file with the .hh extension is a header file specifically used in C++ programming. These files serve as a blueprint for source code…

Programming
.INC

Include File

An INC file is a text-based file used across various programming and scripting languages to store reusable code, declarations, constan…

Programming
.A51

Intel 8051 Assembly Language Source Code File

An A51 file is a source code file written in assembly language specifically for the Intel 8051 microcontroller architecture. This arch…

Programming
.XAML

Extensible Application Markup Language

Extensible Application Markup Language (XAML) is a declarative XML-based language developed by Microsoft that is used for initializing…

Programming
.G4

ANTLR v4 Grammar File

An ANTLR v4 Grammar file, denoted by the .g4 extension, is a source file used by the ANTLR (Another Tool for Language Recognition) par…

Programming
.FXML

JavaFX Scene Builder Layout File

FXML is an XML-based user interface markup language created by Oracle Corporation for defining the user interface of a JavaFX applicat…

Programming
.CXX

C++ Source Code File

A .cxx file is a source code file written in the C++ programming language. It is one of several common extensions used for C++ source…

Programming
.PATCH

Patch File

A patch file is a specialized text document that contains instructions on how to modify a source code file or a set of files. It is ty…

Programming
.STYL

Stylus Stylesheet

Stylus is a preprocessor scripting language that is compiled into Cascading Style Sheets (CSS). It is designed to be a concise, flexible, and expressive way to…

Programming
.HPP

C++ Header File

An HPP file is a header file specifically associated with the C++ programming language. It serves as a container for declarations of classes, functions, consta…

Programming
.SASS

Syntactically Awesome Style Sheets

Sass (Syntactically Awesome Style Sheets) is a preprocessor scripting language that is compiled or interpreted into Cascading Style Sheets (CSS). Sass is a sup…

Programming
.LSP

Lisp Source Code File

An LSP file is a source code file written in the Lisp programming language, which is one of the oldest and most influential high-level programming languages in…

Programming
.XHTML

eXtensible HyperText Markup Language

XHTML (eXtensible HyperText Markup Language) is a markup language that is a reformulation of HTML 4 as an XML application. This means that XHTML documents must…

Programming
.SRC

Source Code File

A file with the .src extension is a generic source code file containing human-readable instructions written in a programming or scripting language. While many…

Programming
.CPP

C++ Source Code File

A .cpp file is a source code file written in the C++ programming language, which is a high-level, general-purpose language that evolved from the original C lan…

Programming
.UNITYPACKAGE

Unity Package File

A Unity Package file, typically with the '.unitypackage' extension, is a proprietary archive format used by the Unity game engine. It functions as a standardiz…

Programming
.VCXPROJ

Visual C++ Project

A VCXPROJ file is a project file used by Microsoft Visual Studio to store information and build settings for a C++ programming project. Introduced with Visual…

Programming
.VLX

AutoCAD Compiled Visual LISP File

The VLX file extension is associated with AutoCAD, a professional computer-aided design (CAD) software developed by Autodesk. It represents a Compiled Visual L…

Programming
.ASM

Assembly Language Source Code File

An ASM file is a source code file written in Assembly language, which is a low-level programming language closely related to machine code instructions. Unlike…

Programming
.HXX

C++ Header File

A file with the .hxx extension is a header file used primarily in C++ programming. It typically contains declarations of classes, functions, variables, and oth…

Programming
.SCM

Scheme Source Code File

The .scm file extension is primarily associated with source code files written in the Scheme programming language, which is a minimalist dialect of Lisp. Schem…

Programming
.CSPROJ

C# Project File

A .csproj file is a project file used by the Microsoft .NET framework to store information about a C# software project. It is an XML-formatted text file that a…

Programming
.PRG

Program File

The .prg file extension is a versatile suffix primarily used to denote program files or source code scripts across several distinct computing platforms and dev…

Programming
.NIB

Interface Builder User Interface File

A NIB file is a resource file used in macOS and iOS development to store user interface designs. The acronym stands for NeXT Interface Builder, reflecting its…

Programming
.HH

C++ Header File

A file with the .hh extension is a header file specifically used in C++ programming. These files serve as a blueprint for source code, containing declarations…

Programming
.INC

Include File

An INC file is a text-based file used across various programming and scripting languages to store reusable code, declarations, constants, or configuration sett…

Programming
.A51

Intel 8051 Assembly Language Source Code File

An A51 file is a source code file written in assembly language specifically for the Intel 8051 microcontroller architecture. This architecture is a staple in t…

Programming
.XAML

Extensible Application Markup Language

Extensible Application Markup Language (XAML) is a declarative XML-based language developed by Microsoft that is used for initializing structured values and ob…

Programming
.G4

ANTLR v4 Grammar File

An ANTLR v4 Grammar file, denoted by the .g4 extension, is a source file used by the ANTLR (Another Tool for Language Recognition) parser generator. ANTLR is a…

Programming
.FXML

JavaFX Scene Builder Layout File

FXML is an XML-based user interface markup language created by Oracle Corporation for defining the user interface of a JavaFX application. It provides a sophis…

Programming
.CXX

C++ Source Code File

A .cxx file is a source code file written in the C++ programming language. It is one of several common extensions used for C++ source files, alongside .cpp and…

Programming
.PATCH

Patch File

A patch file is a specialized text document that contains instructions on how to modify a source code file or a set of files. It is typically generated by a 'd…

Programming

Frequently Asked Questions

Everything you need to know about file extensions

You can search by entering a file extension directly in the search bar or browse the directory by category or alphabetical index.

Each listing provides a definition of the file extension, common use cases, compatible software, supported platforms, and related or alternative formats.

The database is updated regularly to reflect new file extensions, changes in software compatibility, and evolving file format standards.