How to Convert MP4 to MP3 Online
Extract audio from any MP4 video and save it as an MP3 file. Free, fast, and works in your browser — no software needed.
Sometimes you just want the audio. A lecture recording, a music video, a podcast uploaded as a video file — whatever the reason, extracting the MP3 from an MP4 is a quick operation once you have the right tool.
How to Convert MP4 to MP3 Online
- Go to the MP4 to MP3 converter on this site.
- Click Choose File and select your MP4 video.
- Click Convert — the audio track is extracted from the video.
- Download your MP3 file.
The process takes seconds for most files. Larger videos may take a bit longer.
When Would You Do This?
- Saving a lecture or talk. If you recorded a class or webinar as video and just want to listen back, converting to MP3 saves storage and works with any audio player or podcast app.
- Extracting a song. Music videos are typically MP4 files. Converting gives you the audio to play offline.
- Podcasts shared as video. Some creators publish video podcasts on YouTube. MP3 is more convenient for listening on the go.
- Reducing file size. Audio size depends on duration and bitrate. At a constant 192 kbps, 30 minutes of MP3 audio is about 43.2 MB (decimal), plus metadata. The MP4 size depends on its video and audio bitrates; there is no fixed size comparison.
Other Ways to Convert MP4 to MP3
VLC (Free, Desktop)
Open VLC → Media → Convert/Save → Add your MP4 → Choose Audio - MP3 as the profile → Start. VLC is free and works on Windows, Mac, and Linux.
ffmpeg (Command Line)
ffmpeg -i input.mp4 -q:a 0 -map a output.mp3
Fast and reliable. Requires ffmpeg to be installed, but it's the best option if you're converting many files.
On iPhone
Use the Shortcuts app — search the Shortcuts Gallery for audio extraction shortcuts that can process videos from your Photos library.
Frequently Asked Questions
Does the audio quality change when converting from MP4 to MP3? MP3 is lossy, so the audio is re-encoded. Audibility depends on source, encoder settings, playback equipment and listener; no bitrate guarantees an imperceptible difference. Compare a representative passage before sharing.
Can I convert to other audio formats besides MP3? Yes — depending on your needs, you can also convert to WAV (lossless), AAC, OGG, and other audio formats using the audio converters on this site.
My MP4 has no audio. What happens? If the video has no audio track, the conversion will fail or produce an empty file. Make sure your video has audio before converting.
Sources and maintenance
References checked on 2026-10-30. Format capabilities and app support are separate from this site’s output; check the tool’s current options and limitations.