A file viewer is a utility

application software Application software is any computer program that is intended for end-user use not operating, administering or programming the computer. An application (app, application program, software application) is any program that can be categorized as ...

on operating systems, such as

Linux Linux ( ) is a family of open source Unix-like operating systems based on the Linux kernel, an kernel (operating system), operating system kernel first released on September 17, 1991, by Linus Torvalds. Linux is typically package manager, pac ...

macOS macOS, previously OS X and originally Mac OS X, is a Unix, Unix-based operating system developed and marketed by Apple Inc., Apple since 2001. It is the current operating system for Apple's Mac (computer), Mac computers. With ...

, or

Windows Windows is a Product lining, product line of Proprietary software, proprietary graphical user interface, graphical operating systems developed and marketed by Microsoft. It is grouped into families and subfamilies that cater to particular sec ...

. The file viewer is responsible for user access of files located on a data storage device. File viewers allow the user to open and view content on a device, such as a

Personal Computer A personal computer, commonly referred to as PC or computer, is a computer designed for individual use. It is typically used for tasks such as Word processor, word processing, web browser, internet browsing, email, multimedia playback, and PC ...

(PC) or a

mobile phone A mobile phone or cell phone is a portable telephone that allows users to make and receive calls over a radio frequency link while moving within a designated telephone service area, unlike fixed-location phones ( landline phones). This rad ...

Overview

File viewer applications can be categorized based on their functionality: * File Viewer Only applications do not allow the user to edit files. * File Viewer and Converter applications allow viewing data, exporting data in a different

file format A file format is a Computer standard, standard way that information is encoded for storage in a computer file. It specifies how bits are used to encode information in a digital storage medium. File formats may be either proprietary format, pr ...

, and copying information to the clipboard. * File Viewer and Editor applications allow the user to view existing files, modify an existing file's content, or create a new file of a specific type. Differences in functionality are often due to software licensing and proprietary file formats. Some formats can be freely viewed but require specific software for creation or modification. For example, .DBF files created in dBASE could be viewed in Norton Commander, while .PDF files require software like

Adobe Photoshop Adobe Photoshop is a raster graphics editor developed and published by Adobe Inc., Adobe for Microsoft Windows, Windows and macOS. It was created in 1987 by Thomas Knoll, Thomas and John Knoll. It is the most used tool for professional digital ...

, LibreOffice, or

Microsoft Word Microsoft Word is a word processor program, word processing program developed by Microsoft. It was first released on October 25, 1983, under the name Multi-Tool Word for Xenix systems. Subsequent versions were later written for several other platf ...

for editing, whereas Acrobat Reader supports only viewing. To function correctly, a file viewer must interpret the structural information of a file format, such as byte order, character encoding, and newline styles. Media file viewers, such as video players, often rely on

codecs A codec is a computer hardware or software component that encodes or decodes a data stream or signal. ''Codec'' is a portmanteau of coder/decoder. In electronic communications, an endec is a device that acts as both an encoder and a decoder o ...

rather than built-in format support. This approach allows users to extend a media viewer’s compatibility with additional file types. Some editors, such as Audacity, allow users to open files as raw data, a feature sometimes used in glitch art. Additionally, some file viewers act as filters that convert binary files into text (e.g., antiword), though this may result in data loss. Image viewers display graphic files on screen. Some viewers, such as IrfanView, can read multiple graphic file formats, while others, such as JPEGview only support a single format. Common image viewer features include thumbnail preview and creation, image zooming and rotation, color balance and gamma correction, resizing, etc. A

web browser A web browser, often shortened to browser, is an application for accessing websites. When a user requests a web page from a particular website, the browser retrieves its files from a web server and then displays the page on the user's scr ...

functions as a file viewer for

HTML Hypertext Markup Language (HTML) is the standard markup language for documents designed to be displayed in a web browser. It defines the content and structure of web content. It is often assisted by technologies such as Cascading Style Sheets ( ...

and various other file types. While HTML files are stored as plain text, web browsers render them into a structured, human-readable format. Additionally, web browsers can display

multimedia Multimedia is a form of communication that uses a combination of different content forms, such as Text (literary theory), writing, Sound, audio, images, animations, or video, into a single presentation. T ...

files, including images, videos, preformatted documents, and interactive content such as 3D models,

augmented reality Augmented reality (AR), also known as mixed reality (MR), is a technology that overlays real-time 3D computer graphics, 3D-rendered computer graphics onto a portion of the real world through a display, such as a handheld device or head-mounted ...

and

virtual reality Virtual reality (VR) is a Simulation, simulated experience that employs 3D near-eye displays and pose tracking to give the user an immersive feel of a virtual world. Applications of virtual reality include entertainment (particularly video gam ...

elements.

Examples of File Viewers

Plain text files

* Less (Unix) * gedit (Unix) * Most (Unix) * pg (Unix) * More (command) * vi * notepad

Microsoft Office documents

* Microsoft Word Viewer * Microsoft Excel Viewer * PowerPoint Viewer

PDF files

* Adobe Acrobat * Atril * Evince * PDF.js *see :PDF readers

Image files

* Directory Opus * IrfanView * ACDSee * XnView

Video and audio files

* Media Player Classic *

Windows Media Player Windows Media Player (WMP, officially referred to as Windows Media Player Legacy to retronym, distinguish it from Windows Media Player (2022), the new Windows Media Player introduced with Windows 11) is the first media player (application soft ...

* VLC