How to convert MP4, FLAC and WAV to MP3 on a Mac

Old car stereos, some podcast hosts and many upload forms still want MP3. A Mac can make one with QuickTime and the Music app, but it takes two apps for a video and Music won't open FLAC at all. convt turns an MP4, FLAC or WAV file, or a folder full of them, into MP3 with one command, on your Mac, without uploading anything.

Updated November 1, 2026

The short version

WAV: in Music, set Import Using to MP3 Encoder, select the song and choose File › Convert › Create MP3 Version. MP4: export the sound from QuickTime first (File › Export As › Audio Only), then do the same. FLAC, or a whole folder: convt Music --to mp3 -r -o mp3.

Convert to MP3 with QuickTime and the Music app

From Apple's guides Convert a song to a different file format, Convert an M4A file to MP3 on Mac and Export movies in QuickTime Player. We haven't run them ourselves.

The Music app has an MP3 encoder. It works on songs in your library, so a WAV or M4A file goes in first and the MP3 copy lands next to it:

Open Music and choose Music › Settings. Click Files, then Import Settings.
Set Import Using to MP3 Encoder and click OK.
Drag the WAV or M4A file from Finder into Music, then select it.
Choose File › Convert › Create MP3 Version. To find the new file, select it and choose File › Show in Finder.

From an MP4 video: open it in QuickTime Player and choose File › Export As › Audio Only. QuickTime saves an M4A (AAC) file, not an MP3, so run that M4A through the Music steps above.

From FLAC: Apple's guides list MP3, AAC, Apple Lossless, AIFF and WAV for Music. FLAC isn't one of them, and Music doesn't import FLAC files. Use convt or another converter for those.

Every converted song also stays in your Music library, and a folder of files means importing all of them. For more than a few files, the next section is faster.

Convert MP4, FLAC or WAV to MP3 with convt

Run with the released convt 0.5.0 command-line tool on Linux, on files we made. convt encodes MP3 with the same FFmpeg and LAME encoder in the Mac and Windows installs.

convt is a desktop app for Mac and Windows that converts files on your computer, with a command-line tool in the same install. Local conversions never upload your files.

Install it from the download page or GitHub releases. Homebrew also puts the convt command in Terminal:

$ brew tap opencoredev/convt https://github.com/opencoredev/convt$ brew install --cask convt

In Terminal, go to the folder with the file and run one of these. The same --to mp3 works for a video, a FLAC or a WAV. If you installed from the disk image, type /Applications/convt.app/Contents/MacOS/convt instead of convt.

$ convt talk.mp4 --to mp3$ convt 01-opening.flac --to mp3$ convt demo.wav --to mp3

Output

talk.mp4 -> ./talk.mp3

The MP3 is written next to the original, which stays as it was. From an MP4, convt keeps only the sound. MOV, MKV, M4A, AAC, OGG and the other audio and video formats on the formats page convert the same way.

Convert a whole folder to MP3

Give convt a folder instead of a file. -r includes subfolders and -o mp3 writes the MP3s into a new folder with the same subfolders, so an album folder stays an album folder:

$ convt Music --to mp3 -r -o mp3

Output

Music/Live/02-encore.flac -> mp3/Live/02-encore.mp3
Music/Live/01-opening.flac -> mp3/Live/01-opening.mp3
Music/talk.mp4 -> mp3/talk.mp3
Music/demo.wav -> mp3/demo.mp3
4 converted, 0 failed

A folder input converts every file convt can turn into MP3, so videos in the folder get an MP3 of their sound too. Files that are already MP3 are skipped.

What came out of our test

Tags: Title, artist and album carried over from the FLAC files into the MP3s.
Cover art: Dropped. A FLAC with an embedded cover came out as an MP3 without one.
Sample rate: Kept: 44.1 kHz FLAC stayed 44.1 kHz, a 48 kHz WAV stayed 48 kHz.
MP4 video: Only the sound track was written. The video is left out.
Existing MP3s: An MP3 already in the folder was skipped, not converted again.
Name clashes: Running the same command twice wrote talk (1).mp3 next to talk.mp3. It doesn't overwrite the first one.

Pick the bitrate

By default convt uses LAME's variable bitrate at quality 2 (-q:a 2 in FFmpeg terms), which FFmpeg's MP3 guide puts at about 170 to 210 kbit/s for music. The bitrate goes down on quiet or simple sound. To pick a fixed bitrate instead, add --audio-bitrate:

--audio-bitrate 320: The highest MP3 allows, for music you want to keep. Higher numbers are capped at 320.
--audio-bitrate 192: A common setting for music players and car stereos.
--audio-bitrate 128: Fine for speech: lectures, meetings, voice memos and podcasts.

$ convt demo.wav --to mp3 --audio-bitrate 320$ convt Music --to mp3 -r -o mp3 --audio-bitrate 192

In our test, --audio-bitrate 320 gave a 321 kbit/s file and 128 gave 129 kbit/s. MP3 is lossy: converting a FLAC or WAV to MP3 throws away detail you can't get back, so keep the originals.

Questions

Does it keep my song tags and album art?: Tags yes, album art no. Title, artist and album came through from FLAC to MP3 in our test, but an embedded cover was dropped. If the art matters, add it back in Music afterwards.
Does this work on Windows?: Yes, with the same options. The Windows installer doesn't add convt to your PATH, so in PowerShell type its full path: & "$env:LOCALAPPDATA\Programs\convt\convt.exe" Music --to mp3 -r -o mp3.
Should I pick MP3 or M4A?: M4A (AAC) usually sounds as good as MP3 at a lower bitrate, and Apple's apps play it. Pick MP3 when a device or website asks for it, since almost everything plays MP3. convt makes either: --to m4a instead of --to mp3.
Does convt upload my files?: Not for local conversions. The app and the command-line tool convert on your computer. The app uploads a file only if you pick Cloud for a job, which is part of convt Pro. For video, see MOV to MP4 on a Mac.