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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.

6
Indexed file extensions
Popular searches:
.DOCX .7Z .AUTOCAD (DWG, DXF) .PDF .TXT .OBJ (.OBJ)

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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.

Search by extension Enter extensions like PDF, APK, DAT, HEIC, ZIP, or DOCX.
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6 extensions
Programming Letter: A Clear all
.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
.ABNF

Augmented Backus-Naur Form

Augmented Backus-Naur Form (ABNF) is a formal grammar notation used extensively in Internet engineering to define the syntax of protoc…

Programming
.ANE

Adobe Native Extension

An Adobe Native Extension (ANE) is a specialized file format used by developers working with the Adobe AIR (Adobe Integrated Runtime)…

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
.ASP.NET

ASP.NET Web Page

ASP.NET files, typically using the `.aspx` extension (the extension value we'll focus on), are web pages generated using Microsoft's A…

Programming
.ASPX

Active Server Pages Extended

ASPX (Active Server Pages Extended) is a file extension for web pages generated by Microsoft's ASP.NET web framework. These files cont…

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
.ABNF

Augmented Backus-Naur Form

Augmented Backus-Naur Form (ABNF) is a formal grammar notation used extensively in Internet engineering to define the syntax of protocols and data formats. Sta…

Programming
.ANE

Adobe Native Extension

An Adobe Native Extension (ANE) is a specialized file format used by developers working with the Adobe AIR (Adobe Integrated Runtime) platform, now maintained…

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
.ASP.NET

ASP.NET Web Page

ASP.NET files, typically using the `.aspx` extension (the extension value we'll focus on), are web pages generated using Microsoft's ASP.NET framework. These f…

Programming
.ASPX

Active Server Pages Extended

ASPX (Active Server Pages Extended) is a file extension for web pages generated by Microsoft's ASP.NET web framework. These files contain a combination of HTML…

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.