MP4 to MP3 Converter
Convert MP4 to MP3 free — no upload, no signup
To convert MP4 to MP3, drop your MP4 video into the box below and click Convert. Fylo converts with ffmpeg running inside your browser, so nothing is uploaded and there's no signup or watermark. The soundtrack of a 200 MB MP4 is typically extracted in about 10 seconds.
Drop audio files here
or tap to browse · paste with Ctrl+V · add many at once
Your files never leave your device
Advanced
How to convert MP4 to MP3
Add your MP4 videos
Drag and drop MP4 files into the box or tap to choose them. The converter engine (about 31 MB) downloads once, the first time you convert.
Pick a bitrate
192 kbps suits music and 128 kbps or less suits speech. Sample rate and mono/stereo are under Advanced.
Convert and download
Click Convert, then download each MP3 file or all of them as one ZIP.
Why convert MP4 to MP3?
MP4 to MP3 is the quickest way to keep just the audio from a recorded lecture, interview, music video, podcast recording or voice message — smaller files that play on any phone, car stereo or MP3 player, with no battery wasted on video.
What happens when you convert MP4 to MP3?
Fylo skips the video and re-encodes only the AAC audio track to MP3 with LAME at 192 kbps (choose 128 kbps for speech or 320 kbps for music). The MP3 is a tiny fraction of the MP4's size — a 1-hour talk becomes about 86 MB at 192 kbps or 58 MB at 128 kbps.
How does Fylo convert MP4 to MP3?
Fylo decodes the soundtrack of the MP4 (usually AAC) with ffmpeg compiled to WebAssembly and encodes it with the LAME MP3 encoder at 192 kbps (adjustable from 96 to 320 kbps). The video stream is skipped entirely, which is why extraction is fast — the MP3 is a fraction of the video's size. The original sample rate and channel layout are kept unless you change them under Advanced.
What's the difference between MP4 and MP3?
MP4 (MPEG-4 Part 14) is a container format standardised in 2001 and based on Apple's QuickTime file structure. A container holds separately compressed video and audio streams plus metadata such as subtitles, chapters and cover art. Most MP4s use H.264 video and AAC audio; newer files may use H.265 (HEVC) or AV1.
MP3 (MPEG-1 Audio Layer III) was developed largely at Germany's Fraunhofer Institute and standardised in 1993. It removes sounds the ear is unlikely to notice — a technique called perceptual coding — so a 3-minute song takes about 4 MB at 192 kbps instead of about 32 MB as WAV. The last MP3 patents expired in 2017, so it's now free to use.
Learn more: MP4 format guide · MP3 format guide
| Property | MP4 | MP3 |
|---|---|---|
| Type | Video | Audio |
| Contains | Video (H.264, H.265/HEVC, AV1) + audio (AAC, MP3) | Audio only, lossy |
| Developed by | MPEG (ISO/IEC 14496-14) | Fraunhofer IIS / MPEG |
| Introduced | 2001 | 1993 |
| Compatibility | Universal: phones, TVs, editors, social media | Universal |
| Best for | Sharing, uploading, streaming, editing | Music and podcasts on any device |
Frequently asked questions
Does MP4 to MP3 lose quality?
MP4 audio is usually AAC, so converting to MP3 is one more lossy step. At 192 kbps or higher the difference is inaudible for most listeners.
Can I convert an MP4 with no sound?
No — Fylo tells you if the video has no audio track.
Is my MP4 file uploaded to a server?
No. Fylo runs ffmpeg, the same engine used by professional video tools, compiled to WebAssembly inside your browser. Your MP4 file is read directly from your device and never sent anywhere.
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