Reference // 24 formats

Know the format before you convert it.

Choosing the wrong format costs quality you cannot get back. Each guide covers what a format actually is, what it can and cannot do, and which format to pick instead.

Image

7 formats

.jpg

JPG

JPG is a lossy image format published in 1992 and still the most widely supported photo format in existence.

Lossy // 1992

.png

PNG

PNG is a lossless image format from 1996, created as a patent-free replacement for GIF.

Lossless // 1996

.webp

WebP

WebP is an image format released by Google in 2010 that supports both lossy and lossless compression, plus transparency and animation in a single format.

Both // 2010

.avif

AVIF

AVIF is an image format built on the royalty-free AV1 video codec and published in 2019.

Both // 2019

.heic

HEIC

HEIC is Apple's default photo format on iPhone and iPad since iOS 11 in 2017, built on the MPEG HEIF container standardised in 2015.

Lossy // 2015

.svg

SVG

SVG is an XML-based vector image format standardised by the W3C in 2001.

None // 2001

.gif

GIF

GIF dates to 1987 and survives almost entirely because of animation.

Lossless // 1987

Document

3 formats

.pdf

PDF

PDF is a fixed-layout document format created by Adobe in 1993 and an open ISO standard since 2008.

Both // 1993

.docx

DOCX

DOCX is the default Word format since Office 2007 and a published standard as ECMA-376.

Lossless // 2007

.md

Markdown

Markdown is a plain-text formatting syntax from 2004 designed to stay readable as source.

None // 2004

Video

2 formats

.mp4

MP4

MP4 is a container rather than a codec: it usually holds H.264 video with AAC audio, which is the single most widely playable combination on the internet.

Lossy // 2001

.webm

WebM

WebM is a royalty-free video container introduced by Google in 2010, normally carrying VP8, VP9 or AV1 video with Vorbis or Opus audio.

Lossy // 2010

Audio

3 formats

.mp3

MP3

MP3 is the lossy audio format that made digital music portable, standardised as part of MPEG-1 in 1993.

Lossy // 1993

.wav

WAV

WAV stores uncompressed PCM audio, so it is a bit-exact record of the waveform with no encoding loss at all.

Uncompressed // 1991

.flac

FLAC

FLAC compresses audio losslessly, typically to 50-60% of the original WAV size while decoding back to a bit-identical waveform.

Lossless // 2001

3D model

5 formats

.stl

STL

STL describes a 3D surface as nothing but a mesh of triangles.

None // 1987

.glb

GLB

GLB is the single-file binary form of glTF 2.0, the Khronos standard often described as the JPEG of 3D.

Both // 2017

.obj

OBJ

OBJ is a plain-text 3D geometry format from the late 1980s that stores vertices, faces and texture coordinates, with materials in a companion MTL file.

None // 1980s

.fbx