How to Save the Audio From a Video as an MP3

Getting the sound out of a video takes about a minute on any computer. The one decision to make first is the format. MP3 plays almost everywhere, including older car stereos and upload forms that accept only .mp3. But the sound inside most MP4 and MOV files is already AAC, and an M4A file can hold that AAC track exactly as it is. Making an MP3 means encoding already-compressed audio a second time. That is usually fine for speech and casual listening, but it is a step you can skip when the next app accepts M4A.

Steps: MP3 in the browser

1. Open MP4 to MP3 and drop the video into the box. MP4, MOV, WebM and MKV are accepted. Under the file name, the page shows the length, the picture size and the audio format.
2. Pick a quality: 128 kbps (labeled for voice), 192 kbps (labeled as the recommended choice) or 320 kbps (labeled for music). An estimated file size appears below.
3. Click Convert to MP3, then Download MP3. The MP3 keeps the video's file name.

In our test, a 3-minute, 720p MP4 with 160 kbps AAC sound (listed as 46.5 MB) became an MP3 of 4,321,876 bytes at 192 kbps; the page showed 4.1 MB because it counts in 1,024-byte units. Checked with ffprobe, the file was a 3:00 MP3 at 192 kbps, 48 kHz stereo. Our headless test browser used the tool's FFmpeg fallback, and the conversion took 6.3 seconds.

Two behaviors we saw along the way. When we picked 320 kbps for the same video, the page warned: "The original audio is about 160 kbps, so a higher setting only makes the file bigger, not better." And a video with no sound track at all is stopped straight away with "This file has no sound track, so there is no audio to save." The page states that nothing is uploaded; the conversion runs in the browser tab.

Steps: keep the original sound as M4A

1. Open Extract Audio from Video and drop the video in.
2. Choose M4A. If the video's sound is AAC, the page says it will be copied into the M4A as is.
3. Click Convert to M4A and download the file.

With the same 3-minute video, this took 0.2 seconds and produced a 3,635,061-byte M4A. ffprobe showed the same AAC track at about 161 kbps, three minutes long. Nothing was re-encoded, so nothing was lost, and here the file is also smaller than the 192 kbps MP3. If the source's sound is in another codec, that notice does not appear and you get a quality choice instead, because the audio has to be encoded.

Pick M4A when the place you are sending it lists M4A or AAC among accepted formats. Pick MP3 when you are unsure, or when the list says MP3 only.

Steps: QuickTime Player on a Mac

1. Open the video in QuickTime Player.
2. Choose File > Export As > Audio Only.
3. Enter a name, choose where to save it, and click Save.

Apple's QuickTime Player guide says Audio Only produces "an Apple MPEG 4 audio file with an AAC audio track", in other words an M4A, not an MP3. The same page notes that if the Export menu shows no options, the recording may be copyright-protected. If you need MP3 after this, run the M4A through any MP3 converter. Checked on 2026-10-22 against the guide's current macOS version.

Steps: ffmpeg for batches and exact cuts

If you convert many files, or want only part of a long recording, ffmpeg is worth installing. The basic command:

ffmpeg -i input.mp4 -vn -codec:a libmp3lame -qscale:a 2 output.mp3

• -vn leaves the picture out. ffmpeg's documentation describes it, as an output option, as disabling any video stream.
• libmp3lame is the MP3 encoder. The FFmpeg wiki notes that ffmpeg has no MP3 encoder of its own, so you need a build that includes this library.
• -qscale:a 2 asks for variable bitrate. The wiki's table puts this setting at an average of about 190 kbps (range 170 to 210), and says values 0 to 3 normally sound transparent.

To keep only part of the recording, put the start and length before the input: ffmpeg -ss 30 -t 60 -i input.mp4 -vn -codec:a libmp3lame -qscale:a 2 part.mp3 starts at 30 seconds and keeps 60. We ran both commands on our test file and got MP3s of 3:00 and 1:00. If you want a fixed bitrate instead, use -b:a 192k in place of -qscale:a 2; the wiki considers -b:a 320k generally wasteful, since MP3 is lossy either way.

Whose audio it is

Converting a file changes its format, not who owns what is in it. Pulling the sound from your own recordings, a lecture you are allowed to keep, or a clip you have the rights to is the normal use. For anything else, such as music from someone else's video, check the license before you share the MP3.

Sources

• QuickTime Player User Guide: Export movies to other file formats and resolutions
• FFmpeg Wiki: MP3 Encoding Guide
• ffmpeg documentation (options -vn, -ss and -t)