File format reference

A file format determines how data is stored on a computer and how programs should interpret it. Choosing the right format is critical to optimizing file size, maintaining quality, and ensuring compatibility. This guide will help you understand the most popular formats for images, documents, audio, video, and archives so you can make informed decisions in your everyday work and creative work.

Image Formats

Formats for storing raster and vector images. The main tradeoff is between quality, file size, and transparency/animation support.

JPEG/JPG (Joint Photographic Experts Group)

Purpose: Photographs and images with smooth color transitions.

Description: The most common format for photographs. Uses lossy compression, which significantly reduces file size but can introduce artifacts. Does not support transparency or animation. Ideal for web photos where size is important.

PNG (Portable Network Graphics)

Purpose: Images with transparency, logos, graphics with sharp edges.

Description: Uses lossless compression, preserving the crispness of text and lines. Supports full transparency (alpha channel). File size is typically larger than JPEG. Primary choice for web graphics that require a transparent background.

GIF (Graphics Interchange Format)

Purpose: Simple animations and low-quality images with a limited palette.

Description: Supports animation and simple transparency (1 color). Uses a palette of only up to 256 colors, making it a poor choice for photographs. Despite its limitations, it remains popular due to its animation support.

WebP (Web Picture)

Purpose: A modern replacement for JPEG, PNG, and GIF on websites.

Description: A Google format that provides better compression than PNG and JPEG, supporting both lossy and lossless compression. It also includes support for transparency and animation. It is gaining support in all modern browsers.

AVIF (AV1 Image File Format)

Purpose: The next generation of image compression for the web and beyond.

Description: A format based on the AV1 video codec. It provides significantly better quality at the same file size compared to JPEG, WebP, and even PNG. It supports high dynamic range (HDR), deep color palettes, transparency, and animation. It is the most promising format for optimizing web images.

SVG (Scalable Vector Graphics)

Purpose: Vector graphics: icons, logos, diagrams, charts.

Description: Unlike raster formats, SVG is XML-based and describes an image using mathematical shapes and curves. This means it can be scaled to any size without loss of quality. Ideal for responsive web design.

Document Formats

Formats for storing text documents, presentations, and spreadsheets.

PDF (Portable Document Format)

Purpose: Cross-platform document representation.

Description: A format created by Adobe that preserves the precise formatting of a document (fonts, images, layout) regardless of device or operating system. It is a standard for exchanging documents that are not intended to be edited.

DOC/DOCX (Microsoft Word Document)

Purpose: Editable text documents.

Description: DOC is a proprietary format for Microsoft Word, while DOCX is its modern XML-based version (used with Word 2007 and later). DOCX provides better compression and is less likely to corrupt files. It is the primary format for editable text documents.

XLS/XLSX (Microsoft Excel Spreadsheet)

Purpose: Spreadsheets with data, formulas, and charts.

Description: XLS is the original binary Excel format, while XLSX is a modern XML-based format. It is widely used for storing and analyzing structured data.

PPT/PPTX (Microsoft PowerPoint Presentation)

Purpose: Presentations with slides, animations, and multimedia.

Description: Formats for creating and editing presentations. PPTX, like other XML-based formats, offers advantages in file size and data recovery.

TXT (Plain Text)

Purpose: Plain text without formatting.

Description: Contains only text characters without information about fonts, sizes, or colors. The most universal and compatible format, but lacks visual support.

Audio Formats

Formats for storing digital audio.

MP3 (MPEG-1 Audio Layer III)

Purpose: Universal storage and transmission of music.

Description: The most popular audio format, using lossy compression to significantly reduce file size. Provides a good balance between quality and size, although it discards some audio information.

WAV (Waveform Audio File Format)

Purpose: Uncompressed audio recording, professional sound.

Description: Stores audio without compression, providing perfect studio-quality sound. Files are very large, making this format inconvenient for storing music on devices, but critical for recording and editing.

FLAC (Free Lossless Audio Codec)

Purpose: Lossless audio compression for music lovers.

Description: Compresses audio data without loss of quality, similar to ZIP for audio. File size is approximately half that of WAV, while maintaining bit-for-bit identical sound. Popular among audiophiles.

AAC (Advanced Audio Coding)

Purpose: Improved MP3 replacement.

Description: A lossy compression format that provides better audio quality at the same bitrate as MP3. It is the standard for iTunes, YouTube, and many other streaming services.

Video Formats

Container formats for storing video, audio, and metadata.

MP4 (MPEG-4 Part 14)

Purpose: Universal storage and streaming of video.

Description: The most common video format. It is a container that can contain video (usually compressed with the H.264 or H.265 codec), audio (AAC, MP3), and subtitles. It provides good quality at a relatively small file size.

AVI (Audio Video Interleave)

Purpose: One of the first popular video formats.

Description: A legacy container from Microsoft. Can contain video and audio in various codecs, but does not support many modern features (for example, some types of subtitles). Files are typically larger than MP4.

MKV (Matroska Video)

Purpose: Flexible container for movies and TV series.

Description: An open and flexible container format. Can contain virtually any number of video, audio tracks, and subtitles in a single file. Very popular for storing high-quality movies and TV series.

MOV (QuickTime File Format)

Purpose: Video for the Apple ecosystem and professional editing.

Description: A format developed by Apple. Often used to store video shot on the iPhone and in professional video editors. Like MP4, it is based on MPEG-4.

WebM

Purpose: Video for websites.

Description: An open media format designed for use in HTML5. Typically contains video in VP9 or AV1 codec and audio in Vorbis or Opus. Provides high quality with efficient compression.

Archive Formats

Formats for compressing and merging multiple files into one.

ZIP

Purpose: Universal file compression and archiving.

Description: The most popular and cross-platform archive format. Provides lossless compression. Supported on all operating systems without installing additional software. Ideal for everyday use.

RAR (Roshal ARchive)

Purpose: Efficient compression of large files.

Description: Provides better compression than ZIP, especially for large files. Supports multi-volume archives (splitting) and damaged data recovery. WinRAR or similar programs are required to create archives.

7Z (7-Zip Archive)

Purpose: Maximum compression ratio.

Description: An open-source format for the 7-Zip archiver. It uses powerful compression algorithms (such as LZMA), often resulting in smaller archive sizes than ZIP or RAR.

TAR.GZ / TAR.XZ

Purpose: Archiving on Unix-like systems (Linux, macOS).

Description: TAR (Tape ARchiver) first combines files into a single file (without compression), and then compresses this single file using GZ (Gzip) or XZ (LZMA2). This is the standard method for distributing software and backups in the Linux world.