How to Convert WAV to MP3 on Mac (3 Free Methods)

You recorded something and it came out as a WAV. Now it is 400 MB, the upload form has a 25 MB limit, and the person waiting for it does not care about bit depth.

Your Mac converts WAV to MP3 already, with no download and no website in the middle. Three free ways, and one paid one for when it is a folder of two hundred files rather than one.

Quick answer: Open the Music app, go to Music → Settings → Files → Import Settings, set Import Using to MP3 Encoder, click OK. Drag your WAV into the library, select it, then File → Convert → Create MP3 Version.

Pick the method that matches the job

Method 1: the Music app (free, built in)

Apple’s Music app still carries the old iTunes encoder, and it reads WAV without complaint.

Steps:

1. Open Music, then Music → Settings → Files → Import Settings…
2. Set Import Using to MP3 Encoder
3. Under Setting, pick a quality, or choose Custom… to go up to 320 kbps
4. Click OK, then OK again
5. Drag the WAV from Finder into your Music library
6. Select the track, then File → Convert → Create MP3 Version

The MP3 shows up next to the original in your library. To find the actual file, select it and choose File → Show in Finder.

The catch:

Everything happens inside your library, so a loose WAV has to be imported before it can be converted, and afterwards you have two entries cluttering your music. The bitrate is a global setting, not a per-file choice, so changing your mind means going back into Import Settings.

WAV files usually carry no tags either, so the MP3 comes out named after the filename with no artist and no album art.

Method 2: ffmpeg (free, and exact)

When you need a specific bitrate, or the same conversion run over sixty files, this is the shortest path. Install it with Homebrew:

brew install ffmpeg

A good default:

ffmpeg -i input.wav -c:a libmp3lame -q:a 2 output.mp3

-q:a 2 is variable bitrate, which spends more bits on the busy parts and less on the quiet ones. It averages around 190 kbps and sounds better than a fixed 192.

A fixed bitrate, when something demands one:

ffmpeg -i input.wav -c:a libmp3lame -b:a 320k output.mp3

Speech, half the size again:

ffmpeg -i input.wav -c:a libmp3lame -b:a 128k -ac 1 output.mp3

-ac 1 collapses it to mono. On an interview or a voice memo nobody notices, and the file halves.

Every WAV in a folder:

for f in *.wav; do ffmpeg -i "$f" -c:a libmp3lame -q:a 2 "${f%.*}.mp3"; done

The catch:

It is the Terminal, and libmp3lame is the part people forget. Leave -c:a off and ffmpeg still writes an MP3 (it picks the encoder from the extension), but you have given up the control you came for.

Method 3: Audacity (free, with a window)

Reach for Audacity when the WAV needs work before it becomes an MP3: a silent intro trimmed off, a quiet recording brought up, a cough cut out.

Steps:

1. Open Audacity, then File → Open and pick your WAV
2. Edit if you need to, trim the ends, Effect → Volume and Compression → Normalize
3. File → Export Audio…
4. Set Format to MP3 Files
5. Choose Bit Rate Mode (Preset, Variable, Average or Constant) and the quality
6. Click Export

MP3 export works out of the box. Audacity has bundled the LAME encoder since version 2.3.2, so the separate LAME download that every old tutorial insists on is no longer a thing on Mac.

The catch:

It is a full audio editor for a two second job, and it opens one file at a time. Its Macros feature can batch a folder, but setting that up takes longer than learning the ffmpeg line above.

Method 4: Picmal (a folder at a time, one click)

Picmal is the Mac app I build. Drag WAVs in, set the output to MP3, click once.

Steps:

1. Download Picmal from picmal.app
2. Drag in your WAV files, or a whole folder
3. Set the output format to MP3
4. Open the audio options to pick a bitrate, VBR, ABR or CBR, and force mono if it is speech
5. Click Convert

Why people reach for it:

• A folder of hundreds in one pass, each saved as its own MP3
• Bitrate mode, sample rate, bit depth and force mono in one panel instead of a global preference
• It can pull cover.jpg out of the source folder and write it into the MP3, which is worth knowing because a WAV has nowhere to store artwork in the first place
• Runs entirely on your Mac, nothing uploaded, no account, no file size cap
• Sits in the Finder right-click menu, in Shortcuts, and in Raycast, and there is a CLI if you want one

$29 once, updates included, no subscription.

Best for:

A folder rather than a file, or wanting per-job bitrate control without a Terminal window open.

Side-by-side comparison

Why the file gets so much smaller

A WAV holds raw PCM samples. Nothing is compressed, nothing is modelled, the numbers off the converter are simply written to disk. CD standard stereo, 16 bit at 44.1 kHz, works out at 1,411 kbps, and the size is pure arithmetic.

A 3 minute stereo WAV is about 31 MB. The same three minutes as MP3:

So the top MP3 bitrate is roughly a quarter of the WAV, and the bottom one roughly a tenth.

Which bitrate to pick. For music, 192 to 256 kbps covers everyday listening, and 320 is for when it goes to a client, a store, or someone who will complain. For speech, a podcast, an interview, a lecture, 96 to 128 kbps in mono is plenty, and mono halves the file before the bitrate does anything.

Keep the WAV. MP3 discards audio it decides you cannot hear, and that decision is permanent. Convert the MP3 back to WAV and you get a 31 MB file that sounds exactly like the 4 MB one, because the missing data is gone. So the WAV is the master and the MP3 is a copy for sending. Archive the master somewhere, or shrink it to FLAC, which is lossless and roughly half the size.

Common problems

afconvert refuses to write an MP3. It is not your flags. macOS Core Audio ships with no MP3 encoder at all, so afconvert can read MP3 and write AAC, ALAC, AIFF and WAV, and never the one you want. Every Terminal answer that tells you otherwise is wrong. Use ffmpeg.

Shortcuts looks like it should do this. The Encode Media action has an Audio Only switch, which raises hopes, and then offers M4A or AIFF. No MP3. AIFF is uncompressed like WAV, so it solves nothing. A Run Shell Script action calling ffmpeg is the way to get a Shortcut that actually outputs MP3.

The Music app will not import the WAV. Usually a 24 bit or 32 bit float file at 96 kHz out of a DAW. Export a 16 bit 44.1 kHz version first, or skip Music and use ffmpeg, which does not care.

The MP3 has no title or artist. WAV has no proper tag standard, so there was nothing to carry over. Whatever tool you used had to invent the name from the filename. Fix the tags after the conversion, in Music or in the app you keep your library in.

The MP3 came out bigger than expected. You probably converted at 320 kbps out of caution. Drop to 192 and listen once. If you cannot tell, you just saved half.

The short version

• One file, nothing installed: Music → Settings → Files → Import Settings → MP3 Encoder, then File → Convert → Create MP3 Version
• Exact control: ffmpeg -i input.wav -c:a libmp3lame -q:a 2 output.mp3
• Trim or normalize first: Audacity, File → Export Audio, Format MP3
• Do not bother with: afconvert and the Shortcuts Encode Media action, neither writes MP3
• A folder of hundreds: Picmal

Related guides

• Other formats to sort out too? How to convert audio on Mac covers M4A, FLAC, OGG and WAV in both directions, and the audio converter for Mac does a folder in one pass.
• Going the other way? MP3 to WAV is the conversion for getting a file into a DAW, though it will not restore what the MP3 dropped.
• The WAV came out of a video? How to extract audio from a video on Mac covers QuickTime, a Finder Quick Action, VLC and ffmpeg.
• Keeping the master, but smaller? How to convert FLAC to ALAC on Mac covers lossless libraries, tags and album art included.
• The MP3 is still too big? Compress audio on Mac takes it down further without a re-listen test.