How to Convert MP4 to MP3 Online
Follow these three simple steps to extract MP3 audio from an MP4 video. No software installation required. Free and secure.
Select an MP4 Video
Choose an MP4 file containing the audio you want to extract.
Choose the MP3 Audio Settings
Keep the automatic sample rate and channel layout or choose 22.05, 44.1, or 48 kHz and mono or stereo output.
Extract and Download
Start audio extraction, review the MP4 and MP3 file sizes, and download the completed MP3 file.
How Does the MP4 to MP3 Converter Work?
The CompressFly MP4 to MP3 converter reads the first audio stream in your MP4 file, leaves out the video, and re-encodes the extracted sound as a 192 kbps MP3. You can keep the automatic sample rate and channel layout or select the available audio settings before extraction.
Audio extraction runs directly in your browser. Your MP4 file is not uploaded to a server, and the completed MP3 file downloads from the browser to your device.
What "directly in your browser" means
- Your MP4 video is not uploaded to a server.
- Audio extraction and MP3 encoding run locally on your device.
- The completed MP3 file downloads directly from your browser.
When to Convert MP4 to MP3
Extract MP3 audio when you need the sound from an MP4 video without keeping its picture.
Listen to an MP4 Recording
Save speech, music, or other sound from an MP4 lecture, interview, screen recording, or camera video for audio-only listening.
Prepare MP4 Speech for Transcription
Create an MP3 file for transcription, captioning, note-taking, or speech-review software that accepts audio input.
Share Audio Without the Video
Send dialogue, commentary, or other recorded sound separately when the recipient does not need the MP4 picture.
Related MP4 and Audio Tools
MP4 to MP3 Converter FAQ
How do I convert MP4 to MP3 online?
Use this online MP4 to MP3 converter in three steps: 1. Select an MP4 video from your device. 2. Keep or change the available MP3 audio settings. 3. Start extraction and download the completed MP3 file.
What bitrate does the MP4 to MP3 converter use?
The extracted audio is encoded as a 192 kbps MP3. The current converter does not provide a separate bitrate setting.
Can I change the MP3 sample rate and channels?
Yes. Keep the automatic settings or choose 22.05, 44.1, or 48 kHz and select mono or stereo output.
Will converting MP4 to MP3 make the file smaller?
Usually. The MP3 contains audio only and does not include the MP4 video stream. Because the audio is encoded at 192 kbps, the output size depends mainly on its duration.
Is the MP4 to MP3 converter free?
Yes. Convert MP4 to MP3 for free with no registration or credit card required.
Is there a file size limit, and is my MP4 video uploaded?
Your MP4 video is processed locally in your browser and is not uploaded to a server, so there is no server upload limit. The practical limit depends on your device's available memory and processing power, as well as the video's duration and resolution.