Audio Formats Guide - Complete Documentation

Lossless Audio Formats

These formats preserve 100% of the original audio quality with no data loss during compression.

WAV

Waveform Audio File Format

.wav

Lossless / Uncompressed Microsoft & IBM 1991

WAV is the standard uncompressed audio format for Windows. It stores audio in raw PCM format, providing perfect quality but large file sizes. Widely supported across all platforms and audio software.

Best For: Professional audio production, archiving, CD mastering

Sample Rates: 8kHz - 192kHz

Bit Depth: 8, 16, 24, 32-bit

Pros

Perfect audio quality
Universal compatibility
No encoding/decoding required
Industry standard for audio production

Cons

Very large file sizes
No metadata support in basic format
Not ideal for streaming

AIFF

Audio Interchange File Format

.aiff, .aif

Lossless / Uncompressed Apple Inc. 1988

AIFF is Apple's equivalent to WAV, commonly used on macOS and iOS. It stores uncompressed PCM audio with support for metadata and loop points, making it popular in music production.

Best For: Mac-based audio production, sample libraries, professional recording

Sample Rates: 8kHz - 192kHz

Bit Depth: 8, 16, 24, 32-bit

Pros

Perfect audio quality
Native macOS support
Supports metadata and markers
Good for loops and samples

Cons

Large file sizes
Less common on Windows
Limited streaming support

FLAC

Free Lossless Audio Codec

.flac

Lossless / Compressed Xiph.Org Foundation 2001

FLAC provides lossless compression, reducing file sizes by 50-70% while preserving perfect audio quality. It's open-source, royalty-free, and the most popular lossless format for music distribution.

Best For: Music archiving, audiophile collections, lossless music distribution

Sample Rates: 1Hz - 655kHz

Bit Depth: 4 - 32-bit

Pros

Perfect quality with smaller files
Open-source and free
Excellent metadata support
Fast encoding/decoding

Cons

Not supported by all devices
Larger than lossy formats
Limited iOS native support

BWF

Broadcast Wave Format

.wav, .bwf

Lossless / Uncompressed European Broadcasting Union 1997

BWF is an extension of WAV designed for professional broadcast use. It adds metadata chunks for timecode, originator info, and production details required in broadcast environments.

Best For: Broadcast production, film/TV audio, professional archiving

Sample Rates: 44.1kHz - 96kHz typical

Bit Depth: 16, 24-bit

Pros

Professional metadata support
Timecode embedding
Broadcast standard
WAV compatible

Cons

Large file sizes
Specialized use case
Limited consumer support

APE

Monkey's Audio

.ape

Lossless / Compressed Matthew T. Ashland 2000

APE offers higher compression ratios than FLAC but requires more processing power. Popular in Asia for music archiving, though less widely supported than FLAC.

Best For: Music archiving where storage is priority over compatibility

Sample Rates: 8kHz - 192kHz

Bit Depth: 8, 16, 24-bit

Pros

Excellent compression ratio
Perfect audio quality
Good for archiving

Cons

Slow encoding/decoding
Limited device support
Windows-centric
Not open-source

TTA

True Audio

.tta

Lossless / Compressed TTA Team 2004

TTA is a real-time lossless audio codec focused on fast encoding/decoding speeds. It offers good compression with minimal CPU usage, suitable for portable devices.

Best For: Portable lossless audio, real-time applications

Sample Rates: 8kHz - 192kHz

Bit Depth: 8, 16, 24-bit

Pros

Fast encoding/decoding
Good compression
Low CPU usage
Open-source

Cons

Limited software support
Not widely adopted
Few hardware players

MLP

Meridian Lossless Packing

.mlp

Lossless / Compressed Meridian Audio 1999

MLP is the lossless compression used in DVD-Audio and Dolby TrueHD. It supports high-resolution multichannel audio and is designed for home theater applications.

Best For: DVD-Audio, Blu-ray audio tracks, home theater

Sample Rates: Up to 192kHz

Bit Depth: Up to 24-bit

Pros

High-resolution support
Multichannel audio
DVD-Audio/Blu-ray standard
Efficient compression

Cons

Proprietary format
Limited software support
Specialized use

Lossy Audio Formats

These formats use compression algorithms that discard some audio data to achieve smaller file sizes. Quality loss is often imperceptible at higher bitrates.

MP3

MPEG Audio Layer III

.mp3

Lossy / Compressed Fraunhofer Society 1993

MP3 revolutionized digital music by making it practical to store and share audio files. Despite newer formats, it remains the most universally compatible audio format with support on virtually every device.

Best For: Music distribution, podcasts, maximum compatibility

Bitrates: 32 - 320 kbps

Pros

Universal compatibility
Small file sizes
Excellent at high bitrates
Massive ecosystem

Cons

Lossy compression
Less efficient than newer codecs
No native multichannel

AAC

Advanced Audio Coding

.aac, .m4a

Lossy / Compressed ISO/IEC 1997

AAC is the successor to MP3, offering better sound quality at the same bitrate. It's the default format for Apple Music, YouTube, and many streaming services.

Best For: Streaming, mobile devices, Apple ecosystem

Bitrates: 32 - 320 kbps

Pros

Better quality than MP3
Efficient compression
Multichannel support
Streaming-friendly

Cons

Less universal than MP3
Requires licensing
Variable decoder quality

M4A

MPEG-4 Audio

.m4a

Lossy or Lossless / Compressed Apple Inc. 2001

M4A is a file extension for audio-only MPEG-4 files. It typically contains AAC audio but can also hold Apple Lossless (ALAC). It's the standard format for iTunes and Apple Music.

Best For: iTunes library, Apple devices, high-quality portable audio

Bitrates: 16 - 320 kbps (AAC)

Pros

High quality
Great metadata support
iTunes integration
Can be lossless (ALAC)

Cons

Apple-centric
DRM possible
Less universal than MP3

M4R

iPhone Ringtone

.m4r

Lossy / Compressed Apple Inc. 2007

M4R is identical to M4A but with a different extension specifically for iPhone ringtones. The format is recognized by iTunes and iOS for ringtone installation.

Best For: Custom iPhone ringtones and alert tones

Bitrates: 128 - 256 kbps typical

Pros

iPhone native support
Easy ringtone creation
Good quality

Cons

iPhone only
40-second limit for ringtones
Requires iTunes for transfer

OGG Vorbis

Ogg Vorbis

.ogg, .oga

Lossy / Compressed Xiph.Org Foundation 2000

Ogg Vorbis is a free, open-source lossy codec that outperforms MP3 at most bitrates. It's popular in gaming, open-source projects, and Spotify's streaming.

Best For: Gaming audio, open-source projects, web audio

Bitrates: 45 - 500 kbps

Pros

Better than MP3 quality
Open-source and free
Good streaming support
No licensing fees

Cons

Limited hardware support
Not as universal as MP3
Variable browser support

Opus

Opus Interactive Audio Codec

.opus

Lossy / Compressed IETF 2012

Opus is the most advanced lossy codec, excelling at all bitrates from voice to high-fidelity music. It's the standard for WebRTC, Discord, and modern VoIP applications.

Best For: VoIP, streaming, gaming, modern web applications

Bitrates: 6 - 510 kbps

Pros

Best-in-class quality
Excellent at low bitrates
Low latency
Free and open

Cons

Limited legacy support
Newer adoption
Not all hardware supports it

WMA

Windows Media Audio

.wma

Lossy / Compressed Microsoft 1999

WMA was Microsoft's answer to MP3, offering competitive quality and DRM support. While less popular today, it's still found in legacy Windows applications and devices.

Best For: Legacy Windows applications, older portable devices

Bitrates: 32 - 320 kbps

Pros

Good quality at low bitrates
DRM support
Windows integration

Cons

Limited cross-platform support
Declining usage
Proprietary

MP2

MPEG Audio Layer II

.mp2

Lossy / Compressed ISO/IEC 1993

MP2 preceded MP3 and is still used in broadcasting, especially for DAB radio and DVB television audio. It's more robust for broadcast applications but less efficient for storage.

Best For: Digital broadcasting, DAB radio, DVB television

Bitrates: 32 - 384 kbps

Pros

Broadcast standard
Robust error resilience
Low latency encoding

Cons

Less efficient than MP3
Limited consumer use
Larger files

AMR

Adaptive Multi-Rate

.amr

Lossy / Compressed 3GPP 1999

AMR is optimized for speech compression in mobile telephony. It dynamically adjusts bitrate based on network conditions, making it ideal for voice calls and recordings.

Best For: Voice recordings, mobile phone audio, VoIP

Bitrates: 4.75 - 12.2 kbps

Pros

Excellent speech compression
Adaptive bitrate
Mobile standard
Very small files

Cons

Poor for music
Limited frequency range
Voice only

Speex

Speex Codec

.spx

Lossy / Compressed Xiph.Org Foundation 2003

Speex was designed specifically for speech compression with low latency. While largely superseded by Opus, it's still found in legacy VoIP applications.

Best For: Legacy VoIP applications, speech archiving

Bitrates: 2.15 - 44.2 kbps

Pros

Excellent speech compression
Low latency
Open-source
Variable bitrate

Cons

Superseded by Opus
Limited music quality
Declining support

Container & Wrapper Formats

These formats can hold various audio codecs within a standardized container structure.

MKA

Matroska Audio

.mka

Container Matroska.org 2002

MKA is the audio-only variant of the Matroska container (MKV). It can hold any audio codec and supports chapters, tags, and multiple audio tracks.

Best For: Audiobooks with chapters, multi-language audio, audio archives

Sample Rates: Depends on codec

Bit Depth: Depends on codec

Pros

Any codec support
Chapters and metadata
Multiple tracks
Open standard

Cons

Limited player support
Not widely adopted for audio-only
Overkill for single tracks

WebM Audio

.webm

Container Google 2010

WebM is an open media container designed for the web. For audio, it typically contains Opus or Vorbis codecs and is supported by all major browsers.

Best For: Web audio, HTML5 applications, browser-based players

Sample Rates: Up to 48kHz typical

Bit Depth: Depends on codec

Pros

Web native support
Open and royalty-free
Browser compatible
Efficient streaming

Cons

Limited to Vorbis/Opus
Less hardware support
Web-focused

WEBA

WebM Audio

.weba

Container Google 2010

WEBA is an alternative extension for audio-only WebM files, helping distinguish them from video WebM files. Content is identical to .webm audio.

Best For: Web audio where file type clarity is needed

Sample Rates: Up to 48kHz typical

Bit Depth: Depends on codec

Pros

Clear audio-only indication
Same as WebM
Web compatible

Cons

Less recognized extension
Same limitations as WebM

CAF

Core Audio Format

.caf

Container Apple Inc. 2005

CAF is Apple's flexible container format supporting any audio codec, unlimited file size, and rich metadata. It's used extensively in iOS/macOS development.

Best For: iOS/macOS development, long recordings, Apple ecosystem

Sample Rates: Any

Bit Depth: Any

Pros

No file size limit
Any codec support
Rich metadata
Native Apple support

Cons

Apple-centric
Limited cross-platform
Not widely supported

3GA

3GPP Audio

.3ga

Container 3GPP 2001

3GA is the audio-only version of the 3GP container used in mobile phones. It typically contains AMR or AAC audio and is designed for mobile multimedia.

Best For: Mobile phone audio, MMS audio messages

Sample Rates: 8 - 48kHz

Bit Depth: Varies

Pros

Mobile optimized
Small file sizes
Wide mobile support

Cons

Limited to mobile codecs
Low quality typical
Declining use

Surround & Theater Formats

Formats designed for multi-channel audio in home theater and cinema applications.

AC3

Dolby Digital

.ac3

Lossy / Compressed Dolby Laboratories 1991

AC3 (Dolby Digital) is the standard surround sound format for DVDs, Blu-rays, and digital television. It supports up to 5.1 channels of audio.

Best For: DVD/Blu-ray authoring, home theater, digital broadcast

Bitrates: 64 - 640 kbps

Channels: Up to 5.1

Pros

Industry standard
Efficient multichannel
Wide device support
Good quality

Cons

Lossy compression
Licensed format
5.1 maximum

E-AC3

Dolby Digital Plus

.eac3, .ec3

Lossy / Compressed Dolby Laboratories 2004

E-AC3 (Dolby Digital Plus) is an enhanced version of AC3 with higher bitrates, more channels, and better quality. It's used in streaming services and Blu-ray.

Best For: Streaming services, Blu-ray, HDTV

Bitrates: 32 - 6144 kbps

Channels: Up to 7.1 (or 15.1 with JOC)

Pros

Better than AC3
Up to 7.1 channels
Streaming optimized
Backwards compatible

Cons

Licensed format
Less universal than AC3
Higher bandwidth

DTS

Digital Theater Systems

.dts

Lossy / Compressed DTS, Inc. 1993

DTS is a competing surround format to Dolby Digital, often found on DVDs and Blu-rays. It typically uses higher bitrates and is perceived by some as higher quality.

Best For: Home theater enthusiasts, Blu-ray audio tracks

Bitrates: 768 - 1536 kbps typical

Channels: Up to 5.1

Pros

Higher bitrates than AC3
Cinema quality
Good surround imaging

Cons

Larger files
Licensed format
Less universal

TrueHD

Dolby TrueHD

.thd

Lossless / Compressed Dolby Laboratories 2005

Dolby TrueHD provides lossless audio for Blu-ray discs with support for up to 7.1 channels at high resolution. It uses MLP compression internally.

Best For: Blu-ray audio, high-end home theater

Bitrates: Variable (lossless)

Channels: Up to 7.1

Pros

Lossless quality
Up to 7.1 channels
High resolution
Blu-ray standard

Cons

Large files
Blu-ray only typically
Licensed

Professional & Production Formats

Specialized formats used in audio production, broadcasting, and professional workflows.

SD2

Sound Designer II

.sd2

Lossless / Uncompressed Digidesign 1989

SD2 was the native format for Digidesign's Sound Designer II software, widely used in early digital audio workstations. Now largely replaced by modern formats.

Best For: Legacy Pro Tools projects, archival purposes

Sample Rates: Various

Bit Depth: 16, 24-bit

Pros

Professional heritage
Region and marker support

Cons

Legacy format
Limited modern support
Mac-centric

AAF

Advanced Authoring Format

.aaf

Container / Exchange AAF Association 1998

AAF is a professional multimedia interchange format for sharing projects between different software applications while preserving metadata and edit information.

Best For: Post-production workflows, DAW interchange

Sample Rates: Project-dependent

Bit Depth: Project-dependent

Pros

Cross-platform exchange
Preserves edit data
Industry standard

Cons

Complex format
Variable compatibility
Large files

OMF

Open Media Framework

.omf

Container / Exchange Avid Technology 1990s

OMF (OMFI) is a predecessor to AAF used for exchanging projects between audio/video applications. Still used for Pro Tools to other DAW transfers.

Best For: DAW project exchange, video post-production audio

Sample Rates: Project-dependent

Bit Depth: Project-dependent

Pros

Wide DAW support
Preserves edits
Reliable

Cons

2GB file limit
Being replaced by AAF
Limited metadata

ADM

Audio Definition Model

.adm

Metadata Format ITU 2014

ADM is a metadata model for describing immersive and object-based audio. It's used in Dolby Atmos and other next-generation audio formats.

Best For: Dolby Atmos content, immersive audio production

Sample Rates: Project-dependent

Bit Depth: Project-dependent

Pros

Object-based audio
Immersive support
Industry standard

Cons

Complex
Specialized tools needed
Not a traditional audio format

Legacy & Historical Formats

Older formats that were once common but have been largely superseded by modern alternatives.

Sun/NeXT Audio

.au, .snd

Various Sun Microsystems 1980s

AU was the standard audio format for Unix systems and NeXTSTEP. It supported various encodings including μ-law for telephony applications.

Best For: Legacy Unix systems, telephony applications

Sample Rates: 8kHz typical

Bit Depth: 8-bit μ-law typical

Pros

Simple format
Unix heritage
Telephony compatible

Cons

Outdated
Limited features
Rarely used today

VOC

Creative Voice

.voc

Various Creative Labs 1989

VOC was created for Sound Blaster cards and was common in DOS-era games and applications. It supported basic PCM and ADPCM compression.

Best For: DOS game preservation, retro computing

Sample Rates: Up to 44.1kHz

Bit Depth: 8-bit typical

Pros

Historic significance
DOS game compatibility

Cons

Obsolete
Very limited support
Poor quality by modern standards

RealAudio

.ra, .ram

Lossy / Compressed RealNetworks 1995

RealAudio pioneered internet audio streaming in the 1990s. While revolutionary for its time, it has been completely superseded by modern streaming formats.

Best For: Legacy content access only

Bitrates: 6 - 96 kbps typical

Pros

Historic streaming pioneer
Very low bitrate support

Cons

Obsolete
Poor quality
Proprietary
Limited support

ATRAC3

Adaptive Transform Acoustic Coding

.at3, .aa3

Lossy / Compressed Sony 1999

ATRAC3 was Sony's proprietary format used in MiniDisc and early PlayStation devices. Offered good quality but limited to Sony ecosystem.

Best For: MiniDisc transfers, legacy Sony device content

Bitrates: 66 - 132 kbps

Pros

Good compression
MiniDisc standard

Cons

Sony-only
Proprietary
Limited modern support
Superseded

LOAS

Low Overhead Audio Stream

.loas

Container ISO/IEC 2003

LOAS is a low-overhead transport format for AAC audio, designed for streaming applications where minimal overhead is crucial.

Best For: Broadcast streaming, technical applications

Sample Rates: AAC-dependent

Bit Depth: AAC-dependent

Pros

Low overhead
Streaming efficient
AAC transport

Cons

Specialized use
Limited support
Technical format

MIDI & Sequencer Formats

MIDI files don't contain audio but rather musical instructions that synthesizers interpret.

MIDI

Musical Instrument Digital Interface

.mid, .midi

Sequencer Data MIDI Manufacturers Association 1983

MIDI files contain musical performance data (notes, timing, velocity) rather than audio. They're extremely small and can be played through any MIDI synthesizer.

Best For: Music composition, karaoke backing, synthesizer control

Sample Rates: N/A (not audio)

Bit Depth: N/A (not audio)

Pros

Tiny file size
Editable notes
Universal music data
Synthesizer independent

Cons

Not actual audio
Sound depends on playback device
No vocals/samples

Karaoke MIDI

.kar

Sequencer Data + Lyrics Various 1990s

KAR files are MIDI files with embedded synchronized lyrics, designed for karaoke applications. The music is generated by synthesizer.

Best For: Karaoke, lyric display applications

Sample Rates: N/A (not audio)

Bit Depth: N/A (not audio)

Pros

Lyrics included
Small files
Easy to create

Cons

Synthesized sound
Quality varies by player
Not actual recordings

RIFF MIDI

.rmi, .rmid

Sequencer Data Microsoft 1990s

RMID wraps standard MIDI data in a RIFF container, allowing for additional chunks like DLS soundbanks. Used primarily on Windows.

Best For: Windows MIDI applications, custom instrument sounds

Sample Rates: N/A (not audio)

Bit Depth: N/A (not audio)

Pros

Can include soundbanks
Windows native

Cons

Less portable
Larger than standard MIDI
Windows-centric

Hi-Resolution & DSD Formats

Formats designed for audiophile-grade high-resolution audio beyond CD quality.

DSF

DSD Stream File

.dsf

Lossless / 1-bit Sony & Philips 2000s

DSF contains DSD (Direct Stream Digital) audio, the format used for Super Audio CDs. DSD uses 1-bit samples at very high rates (2.8MHz+) for exceptional quality.

Best For: Audiophile collections, SACD rips, high-end playback

Sample Rates: 2.8MHz, 5.6MHz, 11.2MHz

Bit Depth: 1-bit (oversampled)

Pros

Extremely high resolution
SACD format
Audiophile quality
Metadata support

Cons

Very large files
Limited player support
Difficult to edit
Requires special DACs

DFF

DSD Interchange File Format

.dff

Lossless / 1-bit Philips 2000s

DFF is an older DSD container format. Unlike DSF, it has limited metadata support but is otherwise technically similar for DSD audio storage.

Best For: Legacy DSD content, specific player compatibility

Sample Rates: 2.8MHz, 5.6MHz, 11.2MHz

Bit Depth: 1-bit (oversampled)

Pros

DSD quality
Simple format
Some player support

Cons

Poor metadata support
Being replaced by DSF
Large files