How to Extract Audio from a Video (MP4 to MP3)

Sometimes you only want the audio. A conference talk recorded on video, a music performance on YouTube, an interview you want to listen to on a commute. Extracting the audio track from a video file gives you an MP3 you can play anywhere without carrying the full video file.

Extraction vs conversion

There are two ways to get audio from a video. Extraction (also called demuxing) pulls out the existing audio track without re-encoding it — it's instant and lossless because no quality is lost. Conversion re-encodes the audio into a new format, which takes longer and involves a small quality trade-off but gives you control over the output format and bitrate.

For most purposes — getting the audio from a video to listen to — extraction to MP3 is the right approach.

What bitrate to use

• 320 kbps — highest quality, largest files. For music you care about.
• 192 kbps — excellent quality, reasonable size. Good default for most uses.
• 128 kbps — decent quality, smaller files. Fine for voice, podcasts, spoken word.
• 96 kbps or lower — noticeable quality loss. Only for very small file sizes.

Common reasons to extract audio

Converting a recorded meeting or lecture to audio so it's easier to listen to while doing other things. Pulling the soundtrack from a home video. Getting a voice memo off a video you recorded. Separating music from a video performance to add to a playlist.

What if the video has no audio?

Some screen recordings and animated files contain no audio track. If you run extraction on one of these, you'll get an empty or zero-byte output file. This isn't a bug — there simply wasn't anything to extract.

Browser-based audio extraction uses WebAssembly to process the video file entirely on your device. The processing speed depends on your computer's CPU and the size of the video — a 100 MB video typically takes 30–60 seconds. Your video never leaves your machine.