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

Short version: To pull audio out of a video, open it in an editor or converter and export only the audio track — choose MP3 (small, universal) or WAV/AAC (higher quality). Copying the existing track is lossless; converting to MP3 at 192-320 kbps sounds identical for speech. For private files, use a local tool rather than an online uploader.

Maybe you want the audio from a recorded talk, the music from a clip, or a podcast version of a video. Extracting audio means keeping the sound and discarding the picture. Here’s how to do it cleanly.

Pick a format first

• MP3 — small, plays everywhere. Perfect for speech, lectures, and sharing. Use 192 kbps for a good size/quality balance, 320 kbps for music.
• AAC / M4A — often the original audio inside an MP4, so exporting to it can be lossless (a straight copy, no re-encode).
• WAV — uncompressed, maximum quality, large files. Use it if you’ll edit the audio further.

Method 1 — A video editor (most control)

Most editors let you drop in a video and export audio only:

1. Import the video.
2. Choose Export and select an audio-only format (MP3/WAV/AAC).
3. Set the bitrate and export.

This is best when you also want to trim to just the part you need before exporting.

Method 2 — FFmpeg (fast, free, local)

If you’re comfortable with a command line, FFmpeg extracts audio in one step and never uploads anything. A straight copy of the existing audio track is lossless and instant; converting to MP3 re-encodes at whatever bitrate you choose. It’s the tool most desktop apps use under the hood.

Method 3 — Online extractors (convenient, but…)

Web-based “MP4 to MP3” sites work without installing anything, but you’re uploading your video to someone else’s server. For anything private, confidential, or copyrighted, don’t — use a local tool instead. And only extract audio you have the right to use.

The cleaner path: capture the audio right the first time

Often “extract the audio” really means “I recorded something and now I only need the sound.” If you’re recording in the first place, you can capture the audio track cleanly alongside the video and split it out whenever you want.

KeepCast is a local-first screen recorder for Windows that records system audio and your microphone into your MP4 in sync, and its built-in editor can detach the audio from a clip — so you can export just the sound without a separate converter, and without anything leaving your machine. (Join the waitlist.) For getting that audio right at capture time, see how to record system audio and your mic together.

The bottom line

Extracting audio is just exporting a video’s sound as its own file: MP3 for small and universal, WAV/AAC for quality. Use a local editor or FFmpeg to keep private files off the cloud, trim before you export, and — if you’re the one recording — capture the audio cleanly up front so you can split it out any time.