MP3, WAV or M4A? Which Format to Save a Video's Audio In
The short answer
Pick MP3 if you're not sure: it plays on every phone, car, app and website. Pick M4A if the file is going into Apple Music, GarageBand or an iPhone, since it sounds slightly better than MP3 at the same size. Pick WAV only if you'll edit the audio, because it's about ten times bigger. Pick OGG for game engines and open-source software, but not for anything that has to play on an Apple device.
The four formats side by side
| Format | Codec inside | About 1 minute, stereo | Plays on | Best for |
|---|---|---|---|---|
| MP3 | MPEG-1 Layer III | 1 to 2.4 MB | Everything | Sharing, cars, old players, upload forms |
| M4A | AAC (sometimes ALAC) | 1 to 2.4 MB | Apple devices, Android, Windows, most apps | Apple Music, iPhone, GarageBand |
| WAV | PCM, uncompressed | about 10.6 MB | Every editor and computer | Editing, podcasts, samples |
| OGG | Vorbis (usually) | 1 to 2.4 MB | Android, Linux, browsers, game engines; not Apple's apps | Games, web projects, open-source apps |
The compressed sizes depend on the bitrate you choose: 128 kbps is about 1 MB per minute, 320 kbps about 2.4 MB. WAV has no bitrate setting. At 44.1 kHz, 16-bit stereo it's always about 10.6 MB a minute.
What happens to quality when you extract audio
The audio inside a video is almost never uncompressed. Phones, screen recorders and most cameras store AAC at roughly 128 to 256 kbps, and web videos often use Opus. That compressed track is the ceiling. Whatever format you save, the result can't sound better than it.
So there are really two cases. Saving as WAV decodes that track and writes it out without any further loss. Saving as MP3, M4A or OGG decodes it and compresses it again, which loses a little more. At 192 kbps or above, that second round is very hard to hear on speech or ordinary music. At 128 kbps it's fine for voice and noticeable on detailed music through good headphones. My MP3 bitrate guide goes through each setting.
Choosing WAV doesn't upgrade the sound. It only stops it getting worse from here. That matters if you'll edit and export several times, and not at all if you just want to listen.
MP3: the safe default
MP3 is decades old and still the format everything accepts. Car stereos from 2005, smart speakers, podcast hosts, learning platforms and upload forms that only list ".mp3" all take it without question. If the file is leaving your hands, MP3 avoids "it won't play" replies.
Its weakness is efficiency. At the same bitrate, AAC usually sounds a little closer to the source, and MP3 cuts high frequencies sooner at low bitrates. At 192 kbps and up, most people can't tell them apart.
M4A: better sound per megabyte, best on Apple
M4A is the audio-only form of the MP4 container, and it almost always holds AAC, the same codec most videos already use. Apple's apps treat it as native: Music, GarageBand, Voice Memos and CarPlay all open it directly, and it's what QuickTime and the iPhone's Shortcuts app produce when they extract audio.
One catch: Apple also uses the .m4a extension for ALAC (Apple Lossless), which is a different, much larger codec. When you extract audio from a video, you'll almost always get AAC, because the video's audio wasn't lossless to begin with.
Android and Windows play M4A too. The places it fails are old car stereos, some web upload forms and a few older MP3-only players.
WAV: for editing, not for listening
WAV stores the waveform as plain numbers with nothing thrown away. Audacity, GarageBand, Logic, Premiere and DaVinci Resolve all read it instantly, and you don't stack another round of compression every time you export during a project. That's why it's the right choice for podcast interviews, voice-over clean-up, samples and sound effects.
The cost is size. You can estimate it as sample rate × bit depth × channels × seconds ÷ 8. A ten-minute interview in stereo is about 106 MB as WAV and about 14 MB as a 192 kbps MP3. Once you've finished editing, export the final version as MP3 or M4A.
WAV also keeps more than two channels. Pro cameras and field recorders often write four or more audio channels, one per microphone. MP3, M4A and OGG hold stereo at most, so a converter has to mix the mics together. If you need each mic on its own, extract to WAV and split the channels in an editor.
OGG: royalty-free, but skip it for Apple
OGG is a container, and Vorbis is the codec almost always inside it. It's royalty-free, which is why game engines like Godot, many Linux apps and web projects prefer it. Android and every major browser play it.
Apple's apps don't. An OGG file won't play in the iPhone's Music app, and Safari's support depends on the version. If anyone with an iPhone will open the file, choose MP3 or M4A.
A quick pick for common jobs
| What you're doing | Format | Bitrate |
|---|---|---|
| Listening to a lecture or meeting on the go | MP3 | 128 kbps |
| Saving a song or concert clip | MP3 or M4A | 320 kbps |
| Adding audio to Apple Music or an iPhone | M4A | 192 to 320 kbps |
| Editing a podcast or voice-over | WAV | none |
| Using a sound in a video edit or a beat | WAV | none |
| Uploading to a site that asks for .mp3 | MP3 | 192 kbps |
| A sound effect for a game | OGG or WAV | 192 kbps |
| Sending to someone and you don't know their device | MP3 | 192 kbps |
How to save a video's audio in any of these formats
My video to audio converter writes all four. Drop in an MP4, MOV, MKV or WebM file, pick the format and bitrate, and download. It runs in the browser, so it works the same on Windows, Mac, iPhone and Android. Step-by-step guides for each device: iPhone, Android, Windows and Mac.
If you picked the wrong format, convert the original video again rather than converting the audio file. Going MP3 to M4A or the reverse compresses the sound a second time for no benefit.