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How to Convert All MP4 Files to MP3 using Python

Converting video files to audio formats can be useful in various scenarios, such as extracting audio from video clips or preparing audio tracks for podcasts or music libraries. In this tutorial, we’ll explore how to convert a collection of MP4 files to the MP3 format using Python.

MP4 and MP3 are both popular multimedia file formats, with MP4 being primarily used for video and MP3 for audio. Converting MP4 files to MP3 can be advantageous when you only need the audio content of a video file or when you want to reduce file size without compromising audio quality.

Understanding the Code

We’ll be using Python along with the moviepy library to perform the conversion.

Step 1: Installing Required Libraries

Ensure you have the moviepy library installed. You can install it via pip:

pip install moviepy

Step 2: Importing Necessary Libraries

import os
from moviepy.editor import VideoFileClip

We import the necessary libraries:

  • os for file operations.
  • VideoFileClip from moviepy.editor for video manipulation.

Step 3: Converting MP4 to MP3

def mp4_to_mp3(mp4_file):
video = VideoFileClip(mp4_file)
mp3_file = os.path.splitext(mp4_file)[0] + ".mp3"
print(f"Converted {mp4_file} to {mp3_file}")

def convert_all_mp4_to_mp3():
mp4_files = [f for f in os.listdir() if f.endswith(".mp4")]

for mp4_file in mp4_files:

Here, the mp4_to_mp3 function takes an MP4 file path, extracts the audio content, and saves it as an MP3 file. The convert_all_mp4_to_mp3 function finds all MP4 files in the current directory and converts them to MP3 one by one.
Step 4: Running the Conversion

if __name__ == "__main__":

By running this script, all MP4 files in the current directory will be converted to MP3.


In this tutorial, we’ve demonstrated how to convert a collection of MP4 files to the MP3 format using Python. Whether you need to extract audio from video files or prepare audio tracks for distribution, Python provides efficient tools like moviepy to streamline the conversion process.

Experiment with different video and audio file formats, and explore the capabilities of Python libraries to handle multimedia tasks effectively.

Happy coding!