Complete Guide to Audio Formats

Audio formats determine how digital audio files are encoded and stored. This guide covers the most common audio formats — their technical specifications, use cases, and trade-offs — followed by the Hi-Res audio standard.

Lossy Formats

Lossy formats reduce file size by discarding audio data that is less perceptible to the human ear. They are best for portable listening and streaming where storage and bandwidth matter.

MP3 (MPEG-1 Audio Layer 3)

MP3 is the most widely supported audio format. Developed by the Fraunhofer Institute in 1991, it uses lossy compression at bitrates from 128kbps to 320kbps. A 320kbps MP3 file is roughly 1/10 the size of the equivalent WAV file. MP3 is supported by virtually every audio player, phone, and device ever made. The trade-off is quality loss — especially at bitrates below 192kbps, where high frequencies and subtle details are reduced.

AAC (Advanced Audio Coding)

AAC delivers better audio quality than MP3 at the same bitrate. Developed in 1997 as MP3's successor, AAC supports bitrates from 8kbps to 320kbps and multi-channel audio. It is the default format for Apple Music, YouTube, and most streaming services. Compatibility is slightly lower than MP3, but all modern devices support it.

OGG (Vorbis)

OGG Vorbis is an open-source, patent-free alternative to MP3. Developed by the Xiph.Org Foundation, it generally offers better quality than MP3 at comparable bitrates. OGG is widely used in gaming, open-source software, and Spotify's streaming backend. Compatibility on consumer hardware is more limited than MP3 or AAC.

Opus

Opus is the most versatile modern lossy codec. Standardized by IETF in 2012, it supports bitrates from 6kbps to 510kbps with dynamic adjustment. Opus excels at both voice and music, with extremely low latency — making it ideal for real-time communication (WebRTC, Discord, WhatsApp) and high-quality music storage.

M4A (MPEG-4 Audio)

M4A is Apple's container format, typically containing AAC audio. It can also contain ALAC (Apple Lossless). M4A supports rich metadata and cover art, and is the standard format for iTunes purchases and Apple ecosystem audio.

Lossless Formats

Lossless formats compress audio without any quality loss — the decompressed output is bit-for-bit identical to the original. File sizes are larger (typically 2-5x compared to high-bitrate lossy), but audio quality is preserved perfectly.

FLAC (Free Lossless Audio Codec)

FLAC is the most popular lossless audio format. Created by Josh Coalson in 2001, it is open-source and patent-free. FLAC compresses audio to 30-60% of original size while preserving full quality. It supports metadata tags, album art, and is the standard for digital music archiving. Most modern devices and players support FLAC, though Apple devices historically favored ALAC.

WAV (Waveform Audio File Format)

WAV stores uncompressed PCM audio and is the standard for professional audio production. Developed by Microsoft and IBM in 1991, WAV files at CD quality (44.1kHz/16-bit) use approximately 10MB per minute. WAV has universal device support but is impractical for large music collections due to file size.

APE (Monkey's Audio)

APE achieves higher compression ratios than FLAC (around 50% reduction) but with slower encoding/decoding. Developed by Matthew T. Ashland, APE is popular among audiophiles in Asia. Its main drawback is limited device compatibility — it is not supported by most mainstream players outside of specialized software.

DSD (Direct Stream Digital)

DSD uses 1-bit sampling at extremely high rates (2.8MHz or 5.6MHz), producing audio quality that approaches analog recording. Developed by Sony and Philips for Super Audio CD (SACD), DSD offers exceptional dynamic range and frequency response. DSD files are very large and require specialized DAC hardware for playback.

DSF and DFF

DSF and DFF are file formats for storing DSD audio. DSF (Sony) supports metadata tags; DFF (Philips) does not. Both require high-end audio equipment and are used primarily by audiophiles seeking the highest possible playback quality.

Hi-Res Audio Standard

Hi-Res Audio (High-Resolution Audio) is a quality standard defined by the Japan Audio Society (JAS) in 2014. An audio file qualifies as Hi-Res when it meets these specifications:

Parameter	Hi-Res Requirement	CD Quality (baseline)
Sample rate	96kHz or higher	44.1kHz
Bit depth	24-bit or higher	16-bit
Data rate	>1411kbps	1411kbps

Hi-Res primarily applies to lossless formats like FLAC and ALAC. The goal is a listening experience closer to the original studio master recording.

Which Audio Format Should You Choose?

Use case	Recommended format	Why
Everyday listening on phone	AAC 256kbps or MP3 320kbps	Small files, great compatibility
Music archiving / audiophile	FLAC	Lossless, widely supported, open-source
Professional audio editing	WAV	Uncompressed, universal tool support
Hi-Res audiophile systems	DSD/DSF	Maximum possible audio fidelity
Streaming / web apps	Opus	Best quality-to-size ratio, low latency

OnePlayer supports all of the formats listed above — over 20 audio formats in total — including Hi-Res playback up to 192kHz/24-bit.