Best Audio Formats Explained: MP3, AAC, WAV, FLAC and More
A clear guide to the main audio formats, how MP3, AAC, M4A, WAV and FLAC differ, and which one to use for music, podcasts, recording and archiving.
Quick answer: for listening and sharing, use MP3 (most compatible) or AAC/M4A (slightly better quality at the same size). For editing, use WAV. For archiving music without any loss, use FLAC.
There are dozens of audio formats, but only a handful matter for everyday use. They fall into three families.
The three families
Uncompressed formats store the audio exactly as recorded. They are simple and perfect for editing, but very large: WAV and AIFF.
Lossless compressed formats shrink the file like a ZIP archive, without losing a single bit of audio. When decoded, the audio is identical to the original: FLAC and ALAC.
Lossy formats discard sounds that human hearing is unlikely to notice. Files become many times smaller, with a small, often imperceptible loss: MP3, AAC, Opus and Vorbis.
The main formats at a glance
| Format | Family | Compatibility | Best for |
|---|---|---|---|
| MP3 | Lossy | Universal | Sharing, podcasts, any device |
| AAC (M4A) | Lossy | Excellent; the standard on Apple devices | Music on phones, Apple ecosystem |
| Opus | Lossy | Good in browsers and apps; less in older players | Voice, calls, low bandwidth |
| Ogg Vorbis | Lossy | Good on computers and Android | Games, open-source software |
| WAV | Uncompressed | Excellent on computers | Recording, editing, production |
| AIFF | Uncompressed | Excellent on Apple devices | Editing on Mac |
| FLAC | Lossless | Good; improving on Apple devices | Archiving music, high-quality libraries |
| ALAC | Lossless | Apple ecosystem | Lossless music in Apple Music/iTunes |
MP3: the universal choice
MP3 has been around since the 1990s and plays on practically anything with a speaker. At 192 kbps or more, it sounds very good for most music. Its tags (title, artist, album, cover art) are supported everywhere. If you only remember one format, remember this one.
AAC and M4A: better quality at the same size
AAC is the successor to MP3. It is generally more efficient, so a 128–192 kbps AAC file often sounds as good as a higher-bitrate MP3. M4A is simply AAC audio in an MP4 container, and it is the format used by iTunes, Apple Music downloads and many phones. Most videos recorded on phones also store their sound as AAC.
Opus: excellent at low bitrates
Opus is a modern, open format that performs remarkably well at low bitrates, which makes it popular for voice messages, calls and streaming. Support in traditional music players is less complete than MP3 or AAC.
WAV and AIFF: for editing
WAV (Windows origin) and AIFF (Apple origin) usually contain raw, uncompressed audio. They are the standard formats in recording studios and editing software, because they avoid any quality loss when you edit and export repeatedly. Expect about 10 MB per minute of CD-quality stereo.
FLAC: lossless and smaller
FLAC compresses audio without losing anything. Files are typically about half to two-thirds the size of WAV, depending on the music, and they support tags. It is the preferred format for archiving CD collections and high-quality music libraries.
Which format should you use?
| Your goal | Recommended format |
|---|---|
| Play on any device | MP3, 192 kbps |
| Music on iPhone or in Apple Music | AAC (M4A), 192–256 kbps |
| Podcast distribution | MP3 |
| Voice notes and speech | MP3 128 kbps, or Opus if supported |
| Recording and editing | WAV |
| Archiving music with no loss | FLAC |
| An app requires a specific format | Whatever it requires |
Important: conversion can't restore lost quality
Converting a lossy file (MP3, AAC) to a lossless format (WAV, FLAC) does not bring back what was removed. The file becomes bigger but sounds the same. Always keep your best-quality original, and create lossy copies from it.
Convert your files
The Audio Converter converts between MP3, M4A, AAC, WAV and FLAC, and accepts OGG and OPUS files as input. To get audio from a video, use Extract Audio. Everything runs in your browser.
Frequently asked questions
What is the best audio format for quality? Lossless formats (WAV, FLAC, ALAC) preserve the original exactly. Among lossy formats, AAC and Opus are generally more efficient than MP3.
Is M4A the same as MP4? M4A uses the same container as MP4 video, but contains only audio. The different extension helps devices recognize it as music.
Should I convert my MP3 collection to FLAC? No. It would take more space without improving the sound.