How to use the MP4 to MP3 Converter
- Add your MP4 file (up to 50 MB).
- Select a bitrate: 64, 128, 192 or 320 kbps.
- Click Convert and download the MP3 when it is ready.
About MP4 to MP3 conversion
An MP4 file is a container that holds video and audio together. Converting MP4 to MP3 keeps the audio and drops the picture, which gives you a much smaller file you can play on any music player. The audio in most MP4 files is AAC, so the conversion re-encodes it to MP3. Because both formats are lossy, a very slight quality change is normal; use 192 kbps or higher to keep it hard to notice.
Which bitrate should I choose?
| Bitrate | Best for | Approx. size per minute |
|---|---|---|
| 64 kbps | Voice notes, lectures, spoken word | 0.5 MB |
| 128 kbps | Podcasts and everyday listening | 1.0 MB |
| 192 kbps | Music with good quality (default) | 1.4 MB |
| 320 kbps | Highest MP3 quality | 2.4 MB |
MP3 is a lossy format. A higher bitrate cannot add detail that was not in the video's audio, so choosing 320 kbps for a low-quality recording only makes a bigger file.
When MP3 is the right choice
MP3 is the most widely compatible audio format, so it is a good fit for old phones, car stereos, MP3 players and apps that do not accept video. If you do not need that compatibility and want zero extra quality loss, extracting the original AAC audio to an M4A file keeps the sound unchanged, but this tool is built for MP3.
Private by design
The conversion runs inside your browser. Your video is not uploaded to FormatVolt or any other server. The first time you convert, your browser downloads the converter engine (about 30 MB). It is then stored in your browser cache, so later conversions start faster. Conversion speed depends on your device and the length of the file.
Frequently asked questions
How do I convert MP4 to MP3?
Add your MP4 file, choose a bitrate, click Convert, then download the MP3.
Will converting MP4 to MP3 reduce quality?
Slightly, because MP3 is lossy and the audio is re-encoded. At 192 kbps or higher the difference is difficult to hear for most people.
How big will the MP3 be?
About 1 MB per minute at 128 kbps, 1.4 MB per minute at 192 kbps and 2.4 MB per minute at 320 kbps.
Is there a file size limit?
Yes. Each file can be up to 50 MB.
Does it work on a phone?
Yes, in modern mobile browsers. Large files may be slow on older phones, and you should keep the tab open until the conversion finishes.
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Last updated: November 6, 2026