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Batch Extract MP3 from MP4 Videos

Authors
  • avatar
    Name
    Johnson Chang
    Twitter

Extracting audio from multiple video files can be tedious if you do it manually one by one. Whether you’re archiving lectures, creating a music playlist from video files, or just need to separate soundtracks from MP4 videos, automation can save a lot of time. In this guide, you’ll learn how to batch extract MP3 files from MP4 videos using FFmpeg and a short Windows batch script—no manual conversion required.

Tools

  • FFmpeg – a free, powerful command-line tool for audio and video processing
  • Windows Batch Script – to automate repetitive FFmpeg commands

Steps

  1. Install FFmpeg (Windows version)

    • Download the official FFmpeg build from ffmpeg.org.
    • Add the ffmpeg.exe path to your Windows environment variables, or place it in the same directory as your videos.

  2. Create a Batch Script

    • Open Notepad and paste the following script:

      @echo off
for %%a in (*.mp4) do (
    ffmpeg -i "%%a" -vn -acodec libmp3lame -qscale:a 0 "%%~na.mp3"
)

    • Save the file as extract_mp3.bat in the same folder as your MP4 videos.

  3. Run the Script

    • Double-click the .bat file.
    • The script will loop through all .mp4 files and extract their audio as .mp3 in the same directory.

How It Works

  • @echo off — Suppresses command output in the terminal window.
  • for %%a in (*.mp4) — Loops through every MP4 file in the current folder.
  • ffmpeg -i "%%a" — Specifies the input video file.
  • -vn — Excludes video output (audio only).
  • -acodec libmp3lame — Uses the LAME MP3 encoder.
  • -qscale:a 0 — Sets the best audio quality (0 = highest).
  • "%%~na.mp3" — Names the output file after the original video, changing only the extension.

Notes

  • You can adjust -qscale:a to balance file size and quality (e.g., 2 for medium quality).
  • For other audio formats (like .wav or .aac), simply replace the codec and file extension.
  • FFmpeg must be properly installed or located in the same directory for the script to run.

This simple workflow automates what would otherwise be a repetitive task. With FFmpeg and a batch file, you can convert entire folders of MP4 videos into MP3s in seconds — ideal for podcasting, music archiving, or quick audio extraction.