Convert MP4 to MP3
Extract audio from any MP4 video and save it as a high-quality MP3 file — directly in your browser. Perfect for saving music, podcasts, or voiceovers from video. No upload needed.
Drag 'n' drop files here, or
click to select files
.mp4
Drop your files and click Convert to get MP3
//when_to_use
When to Convert MP4 to MP3
- Saving background music from YouTube videos downloaded as MP4
- Extracting podcast audio from video recordings for publishing to Spotify or Apple Podcasts
- Creating audio clips from lectures or webinar recordings for offline listening
- Pulling voiceover tracks from video projects for reuse in other productions
- Converting screen recordings to audio-only for transcription services
//comparison
MP4 vs MP3
| Property | MP4 | MP3 |
|---|---|---|
| Type | Video container (H.264 + AAC) | Audio only |
| Typical file size (3 min) | 30-100 MB | 4-6 MB |
| Audio quality | 128-320 kbps AAC | 192 kbps MP3 |
| Device support | Universal | Universal |
| Streaming support | YouTube, browsers | All music players |
| Contains video | Yes | No — audio only |
//how_it_works
How It Works
Drop your MP4 video
Drag and drop or select an MP4 video file. The first conversion loads the FFmpeg engine (~30MB) — subsequent conversions are instant.
FFmpeg loads in browser
FFmpeg compiled to WebAssembly runs entirely in your browser. No server, no upload. The engine initializes once and stays cached for the session.
Audio extraction at 192kbps
FFmpeg strips the video track (-vn flag) and re-encodes the audio using the LAME MP3 encoder at 192kbps constant bitrate — high quality, small file.
Download your MP3
Your audio file is ready — typically 90-95% smaller than the original video. Perfect for music players, podcasts, or offline listening.
// under the hood
Our converter uses FFmpeg compiled to WebAssembly (ffmpeg.wasm) running entirely in your browser. It extracts the audio stream from the MP4 container and re-encodes it using the LAME MP3 encoder at 192kbps constant bitrate. The video stream is discarded with the -vn flag. MP4 files typically contain AAC audio, which is decoded and re-encoded to MP3.
//faq
Frequently Asked Questions
- How does MP4 to MP3 conversion work?
- Our tool extracts the audio track from your MP4 video file and encodes it as a high-quality MP3 (192kbps). The video track is discarded, giving you a much smaller audio-only file. Everything runs in your browser using WebAssembly — no server upload required.
- What quality is the MP3 output?
- We encode at 192kbps, which is considered high quality for MP3 and is indistinguishable from the original audio for most listeners. This bitrate provides an excellent balance between file size and audio quality.
- Can I extract audio from long videos?
- Yes, but since conversion happens in your browser, longer videos take more time and memory. Videos under 500MB work best. For very large files, you may notice slower performance depending on your device.
- Will this work with any MP4 file?
- Yes — our converter handles MP4 files with any audio codec (AAC, MP3, AC3, etc.). As long as the MP4 contains an audio track, it will be extracted and converted to MP3.
- Are my files private?
- Absolutely. Your video files never leave your device. All processing happens locally in your browser using FFmpeg compiled to WebAssembly. We have zero access to your files.