File Format Encyclopedia

Portable Network Graphics

PNG is a lossless raster image format that supports transparency. It was created as an improved, non-patented replacement for GIF and is the most widely used lossless image format on the web.

Joint Photographic Experts Group

JPEG is the most widely used lossy image compression format, particularly for photographs. It achieves significant file size reduction by discarding visual information that the human eye is less sensitive to.

High Efficiency Image Container

HEIC is Apple's default image format since iOS 11 and macOS High Sierra. It uses HEVC (H.265) compression to produce images that are roughly half the size of equivalent JPEG files while maintaining the same visual quality.

Web Picture Format

WebP is a modern image format developed by Google that provides superior lossless and lossy compression for web images. It supports transparency and animation, making it a versatile replacement for PNG, JPEG, and GIF.

Graphics Interchange Format

GIF is one of the oldest image formats still in wide use, primarily for short animations and simple graphics. It supports up to 256 colors and frame-based animation.

Scalable Vector Graphics

SVG is an XML-based vector image format for 2D graphics. Unlike raster formats, SVG images can be scaled to any size without losing quality, making them perfect for logos, icons, and responsive web graphics.

AV1 Image File Format

AVIF is a modern image format based on the AV1 video codec, developed by the Alliance for Open Media. It offers significantly better compression than JPEG and WebP — typically 30-50% smaller files at the same visual quality. As of 2026, AVIF has 93% browser support.

JPEG XL

JPEG XL is the next-generation image format designed to replace both JPEG and PNG. It offers superior compression, supports both lossy and lossless modes, and can losslessly transcode existing JPEG files to 20% smaller sizes. Chrome re-enabled JXL support in January 2026.

Tagged Image File Format

TIFF is a flexible, lossless image format widely used in professional photography, printing, and publishing. It supports multiple color spaces, layers, and extremely high bit depths.

Bitmap Image File

BMP is an uncompressed raster image format native to Windows. It stores pixel data directly, resulting in large files but zero quality loss and fast rendering.

Windows Icon

ICO is the standard format for application icons on Windows and favicons on websites. A single ICO file can contain multiple image sizes and color depths.

Portable Document Format

PDF is a file format developed by Adobe for presenting documents consistently across all platforms and devices. It can contain text, images, vector graphics, forms, multimedia, and digital signatures.

Microsoft Word Open XML Document

DOCX is the default file format for Microsoft Word documents since Office 2007. It's an XML-based format stored in a ZIP container, making it more compact and recoverable than the older DOC format.

Microsoft Excel Open XML Spreadsheet

XLSX is the default file format for Microsoft Excel spreadsheets since Office 2007. It stores data, formulas, charts, and formatting in a ZIP-compressed XML container.

Microsoft PowerPoint Open XML Presentation

PPTX is the default format for Microsoft PowerPoint presentations since Office 2007. It stores slides, animations, media, and formatting in a ZIP-compressed XML container.

Plain Text File

TXT is the simplest file format — plain text with no formatting. It's universally compatible, human-readable, and the foundation of all text-based computing.

Rich Text Format

RTF is a document format developed by Microsoft that supports basic text formatting (bold, italic, fonts, colors) while remaining readable by most word processors.

MPEG Audio Layer III

MP3 is the most widely recognized digital audio format. It uses lossy compression to reduce audio files to roughly one-tenth their original size while maintaining acceptable sound quality for most listeners.

Waveform Audio File Format

WAV is an uncompressed audio format developed by Microsoft and IBM. It stores raw audio data with no compression, preserving perfect audio quality at the cost of very large file sizes.

Free Lossless Audio Codec

FLAC is the most popular lossless audio compression format. It reduces audio file sizes by 50-70% compared to uncompressed WAV without any quality loss — the decoded audio is bit-for-bit identical to the original.

Advanced Audio Coding

AAC is a lossy audio compression format designed as the successor to MP3. It delivers better sound quality than MP3 at the same bitrate and is the default audio format for Apple devices, YouTube, and most streaming platforms.

Ogg Vorbis

OGG is a free, open-source audio format that provides quality comparable to MP3 and AAC without any patent restrictions. It's widely used in gaming, web audio, and open-source applications.

MPEG-4 Part 14

MP4 is the most widely used video container format, capable of storing video, audio, subtitles, and metadata. It supports H.264 and H.265 video codecs and is the standard format for web video, streaming, and mobile devices.

Apple QuickTime Movie

MOV is Apple's video container format used by QuickTime and iPhones. It can contain video, audio, subtitles, and metadata using various codecs including H.264, H.265/HEVC, and ProRes.

WebM Video

WebM is an open, royalty-free video format developed by Google for the web. It uses VP8/VP9 (or AV1) video codecs and Vorbis/Opus audio codecs, providing efficient compression for web streaming.

JavaScript Object Notation

JSON is a lightweight data interchange format that is easy for humans to read and write and easy for machines to parse and generate. It has become the dominant data format for web APIs and configuration files.

Comma-Separated Values

CSV is a simple text format for storing tabular data where each line is a row and values are separated by commas. It's universally supported by spreadsheet applications, databases, and programming languages.

Extensible Markup Language

XML is a markup language designed to store and transport data in a human-readable and machine-readable format. It's widely used in web services, configuration files, and data interchange.

JavaScript Source File

JavaScript (.js) files contain code that runs in web browsers and Node.js environments. It's the most widely used programming language in the world, powering interactive websites, servers, mobile apps, and more.

TypeScript Source File

TypeScript (.ts) files contain typed JavaScript code. TypeScript adds static type checking to JavaScript, catching bugs before they reach production. It compiles to standard JavaScript.

HyperText Markup Language

HTML is the standard markup language for creating web pages. Every website you visit is built with HTML, which defines the structure and content of the page.

Cascading Style Sheets

CSS files define the visual presentation of HTML documents — colors, fonts, layouts, animations, and responsive design. CSS is one of the three core technologies of the web alongside HTML and JavaScript.

YAML Ain't Markup Language

YAML is a human-friendly data serialization language used extensively for configuration files, CI/CD pipelines, and infrastructure-as-code. It uses indentation instead of brackets, making it cleaner to read than JSON or XML.

Markdown

Markdown is a lightweight markup language for creating formatted text using a plain-text editor. It's the standard for README files, documentation, blog posts, and note-taking apps.

ZIP Archive

ZIP is the most widely used archive format for compressing and bundling multiple files into a single package. It's natively supported by Windows, macOS, and Linux without any additional software.