MP4 to MP3 Converter

1. Upload one MP4, M4V, or MOV video (up to 500 MB).
2. Click 'Convert to MP3' — video-to-audio conversion runs faster than real-time.
3. Download the MP3 when conversion completes.

MP4 files can be 10-50x larger than the audio they contain. Converting MP4 to MP3 strips out the video stream entirely — a 100 MB video becomes a 3-5 MB audio file, perfect for listening on any device.

MP4 files carry both video and audio streams. When you only need the audio — a podcast, lecture, interview, or music video — keeping the video stream wastes storage and prevents playback on audio-only devices. Converting MP4 to MP3 extracts just the audio track, producing a compact file that plays on every MP3 player, car stereo, phone, and music app.

The converter uses FFmpeg to demux the audio stream from the MP4 container and re-encode it as MP3 using the LAME encoder at VBR ~190 kbps. Video and subtitle streams are discarded. If the source audio was already in a compatible codec (AAC), the conversion is straightforward. The resulting MP3 file is typically 3-5 MB per minute of audio.

• Extracting audio from a YouTube or social media video download.
• Saving a lecture, interview, or podcast from a recorded MP4.
• Converting a music video MP4 to MP3 for your phone's music player.
• Ripping audio from a screen recording or webinar.
• Making an audiobook or voice memo MP3 from a video recording.
• Preparing audio for a car stereo USB drive that only plays MP3.
• Extracting the audio track from a large MP4 to save storage space.

MP3 output uses LAME VBR ~190 kbps, which is transparent quality — indistinguishable from the source for most listeners in blind listening tests. The conversion discards the video stream entirely. Audio quality matches the source audio track: if the source was already heavily compressed, the MP3 output is limited by the source, not the encoder.

• Videos without an audio track cannot be converted — the tool returns an error.
• MP3 is a lossy format; repeated re-conversions accumulate artifacts.
• Video files over 500 MB are rejected — split them first.
• Multichannel surround audio (5.1) is downmixed to stereo.
• Subtitles and video effects are discarded.

• Output MP3 plays on every device: phones, tablets, computers, car stereos, portable MP3 players.
• Supported by every music app: Spotify (local files), iTunes, Windows Media Player, VLC.
• Accepted by every music distribution platform: SoundCloud, Bandcamp, podcast hosts.
• Native support in every OS released in the last 25 years.
• Works with all car stereo head units that support USB or SD card playback.

• Use MP3 output for universal playback — every device plays MP3.
• Keep the original MP4 if you may need the video later.
• VBR ~190 kbps is transparent quality — you won't hear a difference.
• For lossless audio, use MP4 to WAV instead.
• Batch-convert multiple MP4 files in one session.

Conversion says 'no audio track found'

The MP4 file has no audio stream — it was recorded silently or the audio track was stripped. Check the source file; if it plays audio in a video player, re-download the MP4 and try again.

MP3 output is unexpectedly quiet or loud

Some MP4 files have inconsistent audio levels. The converter does not apply volume normalization by default. Use an audio editor or the optional normalization setting if available.

MP3 output is much larger than expected

Typical MP3 output is ~1 MB per minute of audio at VBR ~190 kbps. If your file is significantly larger, the source video may have been lossless or extremely high bitrate. Output size still depends on source audio quality.

• ISO/IEC 14496-14 — MP4 File Format Specification
• ISO/IEC 11172-3 — MPEG-1 Audio Layer III (MP3)
• LAME Project — MP3 Encoder Documentation