1 Understanding Digital Audio Formats
Digital audio formats are containers that store audio data using different encoding methods. The format you choose affects file size, audio quality, compatibility, and suitability for different tasks. Understanding these tradeoffs helps you make informed decisions throughout your production and distribution workflow.
All digital audio starts as raw PCM (Pulse Code Modulation) data—a series of amplitude values sampled at regular intervals. What distinguishes different formats is how this data is stored: uncompressed (exactly as sampled), lossless compressed (smaller but perfectly reconstructible), or lossy compressed (smaller but with permanent quality reduction).
The format wars of the early digital age have largely settled into clear use cases. Uncompressed formats dominate production. Lossless formats serve archival and audiophile needs. Lossy formats enable streaming and portable playback. Understanding when to use each type is fundamental to professional audio work.
Quality isn't just about the format—sample rate and bit depth matter equally. A 16-bit/44.1kHz FLAC is identical to a 16-bit/44.1kHz WAV in audio quality. The format determines how that quality is packaged, not what the quality is. Use our Audio File Size Calculator to understand how these parameters affect storage requirements.
2 Uncompressed Audio Formats
Uncompressed formats store raw PCM data with minimal overhead. They offer maximum compatibility and zero processing latency, making them the standard for recording, editing, and mixing. The tradeoff is large file sizes.
WAV (Waveform Audio File Format)
Overview: Developed by Microsoft and IBM, WAV is the universal standard for uncompressed audio. Nearly every piece of audio software and hardware supports WAV without question. The format can store audio at any sample rate and bit depth supported by the PCM standard.
Technical details: WAV uses RIFF (Resource Interchange File Format) container structure. Standard WAV supports up to 4GB file size, though extended formats exist for larger files. Metadata support is limited compared to newer formats.
Best for: Recording, editing, mixing, mastering, stem exports, anything where compatibility and editability matter more than file size. WAV is the safest choice when you're unsure what format to use.
AIFF (Audio Interchange File Format)
Overview: Apple's equivalent to WAV, AIFF stores identical audio quality in a different container structure. Common in Mac-based production environments and professional studios with Apple hardware.
Technical details: Based on IFF (Interchange File Format) structure. AIFF-C variant supports compression but is rarely used. Better metadata support than WAV through chunk-based architecture.
Best for: Mac-centric workflows, Logic Pro users, situations where you need uncompressed audio in Apple ecosystems. Functionally interchangeable with WAV for audio quality.
3 Lossless Compressed Formats
Lossless compression reduces file size without losing any audio information. The decoded output is bit-for-bit identical to the original. This makes lossless formats ideal for archival and distribution where quality cannot be compromised but storage matters.
FLAC (Free Lossless Audio Codec)
Overview: The dominant open-source lossless format. FLAC typically achieves 50-60% compression on typical music, meaning a 100MB WAV becomes a 40-50MB FLAC with zero quality loss. Widely supported across platforms and devices.
Technical details: Uses linear prediction and entropy coding. Compression levels 0-8 trade encoding time for file size (level 5 is the default sweet spot). Supports up to 8 channels, 32-bit depth, and 655kHz sample rate—far beyond practical needs.
Best for: Music archival, audiophile distribution, any situation where you need smaller files but cannot accept quality loss. FLAC is the standard for lossless music downloads.
ALAC (Apple Lossless Audio Codec)
Overview: Apple's proprietary lossless codec, now open-source. Similar compression ratios to FLAC. Required for lossless playback on Apple devices and integration with iTunes/Apple Music ecosystem.
Technical details: Similar compression methods to FLAC. Stored in MP4/M4A containers. Full support in Apple ecosystem, variable support elsewhere.
Best for: Apple device users who want lossless quality, iTunes library organization, situations requiring Apple ecosystem compatibility.
4 Lossy Compressed Formats
Lossy compression achieves dramatic file size reduction by permanently removing audio data deemed inaudible by psychoacoustic models. Modern lossy codecs at high bitrates approach transparency—most listeners cannot distinguish them from lossless under normal conditions.
MP3 (MPEG-1 Audio Layer III)
Overview: The format that enabled the digital music revolution. Despite being technically superseded, MP3 remains the most universally compatible lossy format. Every device and software supports MP3.
Technical details: Uses perceptual coding based on psychoacoustic masking. Quality scales with bitrate: 128kbps (acceptable), 192kbps (good), 256kbps (very good), 320kbps (near-transparent). VBR (Variable Bit Rate) optimizes quality-per-byte.
Best for: Universal sharing, maximum compatibility, situations where you need guaranteed playback on any device. Use 320kbps for quality-critical applications.
AAC (Advanced Audio Coding)
Overview: The successor to MP3, AAC delivers better quality at equivalent bitrates. Standard format for Apple devices, YouTube, and many streaming services. More efficient encoding makes it preferable when compatibility allows.
Technical details: Improved transform coding and better handling of transients compared to MP3. Supports higher sample rates and more channels. 256kbps AAC roughly equals 320kbps MP3 in quality.
Best for: Streaming delivery, Apple ecosystem, video soundtracks, situations where you control the playback environment and can ensure AAC support.
OGG Vorbis and Opus
Overview: Open-source alternatives to MP3/AAC. Vorbis is used by Spotify. Opus is newer and excels at both music and voice, becoming the standard for web communication (WebRTC).
Best for: Game audio (Vorbis), web applications and voice communication (Opus), open-source projects, situations where licensing costs matter.
5 Choosing the Right Format
Format selection should be driven by use case, not preference. Each stage of the audio workflow has optimal format choices based on practical requirements.
Recording and Editing
Always use uncompressed formats (WAV/AIFF) for recording. Compression during recording wastes CPU cycles and offers no benefit since you'll be working with the files repeatedly. DAWs work most efficiently with uncompressed audio, and you preserve maximum flexibility for editing.
Mixing and Processing
Continue using uncompressed formats throughout mixing. Every time you bounce, export, or render, use WAV. Processing lossy files and re-encoding causes quality degradation. Even lossless compression adds unnecessary encode/decode overhead during active production.
Archival
For long-term storage, lossless compression offers compelling benefits. FLAC cuts storage needs roughly in half with zero quality penalty. Archive your WAV masters, then create FLAC copies for backup storage. The space savings become significant for large libraries.
Distribution
Match format to destination. Streaming platforms specify their preferred formats. CD distribution requires 16-bit/44.1kHz. Audiophile distribution uses FLAC or ALAC. General sharing uses MP3 for maximum compatibility. Let the destination drive the choice.
6 Professional Production Workflow
A clear format strategy prevents confusion and quality loss throughout the production process.
Recording Phase
Record at 24-bit minimum, 48kHz or higher sample rate, to WAV or AIFF. Higher bit depth provides headroom and noise floor benefits even if final delivery is 16-bit. The slight increase in file size is negligible compared to the quality insurance.
Production Phase
Keep everything in native DAW formats or uncompressed audio. Never import lossy files for serious production work—the quality loss compounds with each processing stage. If you must use lossy sources (samples, etc.), acknowledge the limitation and don't expect to improve upon it.
Delivery Phase
Export masters as high-resolution WAV (24-bit, session sample rate). Create delivery formats from this master: dithered 16-bit for CD, FLAC for audiophile distribution, AAC/MP3 for streaming. Never encode lossy from lossy—always return to the lossless master.
7 Streaming and Distribution Requirements
Major distribution channels have specific format requirements. Understanding these helps you prepare appropriate deliverables.
Streaming Services
Spotify: Accepts WAV or FLAC, transcodes to OGG Vorbis at various quality levels (96-320kbps depending on user subscription and connection).
Apple Music: Accepts ALAC, AAC, or WAV. Offers lossless streaming to subscribers. Submit highest quality available.
Tidal: Focuses on high-quality streaming. Submit FLAC for MQA encoding or standard lossless tiers.
Generally, submit the highest quality your distributor accepts. They handle transcoding to their delivery formats with professional-grade encoders optimized for their platform.
Download Sales
Offer multiple formats when possible. FLAC for audiophiles, MP3 320 for compatibility. Some platforms handle this automatically; others require you to upload multiple versions. Check your distributor's capabilities.
8 The Future of Audio Formats
Audio format evolution continues, driven by new technologies and changing consumption patterns.
Immersive Audio
Dolby Atmos and Sony 360 Reality Audio are pushing beyond stereo. These formats require new container types and encoding methods to store spatial information. As immersive audio grows, expect format requirements to evolve accordingly.
High-Resolution Streaming
Bandwidth improvements enable higher quality streaming. Apple Music's lossless tier and Amazon Music HD signal industry movement toward quality streaming. Your archives should be prepared for these higher-quality delivery channels.
Codec Improvements
New codecs like Opus continue improving efficiency. Future lossy codecs may achieve transparency at even lower bitrates. However, the fundamental categories—uncompressed, lossless, lossy—will persist. Understanding these principles prepares you for whatever specific formats emerge.
For help navigating format requirements for your specific project, our Mixing Services include delivery in any format required by your distribution channels.