Free MP4 to MP3 Converter — Extract Audio Online
Extract audio from MP4 videos and save as MP3 files. Browser-based converter using FFmpeg WebAssembly — fast, free, and completely private.
Drag & drop or click to upload an MP4 video
Supports .mp4 and other video files
Video Info
Audio Preview
Powered by FFmpeg WebAssembly. All processing happens locally in your browser.
Video → Audio in Seconds
Need the audio from a video? Our MP4 to MP3 converter strips away the video and gives you a clean MP3 file. Perfect for podcasts, lectures, music, and audiobooks — all processed privately in your browser.
Key Features
High-Quality Audio
Choose from 128 to 320 kbps bitrate for studio-quality audio extraction.
Multiple Formats
Works with MP4, WebM, MOV and other common video containers.
In-Browser Playback
Preview the extracted audio directly in your browser before downloading.
Adjustable Quality
Fine-tune the output bitrate to balance between file size and audio clarity.
Common Use Cases
Podcasts
Extract audio from video podcasts for audio-only distribution
Music
Save audio from music videos for offline listening on any device
Lectures
Convert recorded lectures to audio for studying on the go
How this Free MP4 to MP3 Converter — Extract Audio Online works
This audio extraction tool converts MP4 video files to MP3 audio format entirely in the browser using FFmpeg.wasm, a WebAssembly port of the industry-standard FFmpeg multimedia framework. Users upload MP4 files through drag-and-drop or file selection, choose output bitrate (128, 192, 256, or 320 kbps) controlling audio quality versus file size, and monitor conversion progress through a real-time progress bar. The converter loads FFmpeg's WebAssembly core, writes the input video to virtual filesystem, executes audio extraction with configurable encoding parameters, then reads the output MP3 for preview and download. Built-in audio playback enables quality verification before saving, while file size comparison shows original video versus extracted audio sizes. Applications include extracting music from video recordings, saving podcast audio from video platforms, creating audio tracks from lecture recordings, or isolating soundtracks from home videos for portable listening.
How to Use
Upload MP4 video
Drag and drop or click to select an MP4 video file from your device.
Choose bitrate
Select audio bitrate — higher values mean better quality but larger files.
Extract & download
Click Convert to extract audio, then download the MP3 file.
Example Usage
Audio extracted from a lecture video, perfect for listening on the go.
Frequently Asked Questions
How does MP4 to MP3 conversion work?
What bitrate should I choose?
Is there a file size limit?
Why do I see a SharedArrayBuffer error?
Is my video data safe?
Related Tools
Sine Wave Generator
Generate and visualize custom sine waves online.
Playback Speed Calculator
Calculate time saved when watching videos at faster speeds (1.25x, 1.5x, 2x).
Online Tone Generator
Generate pure audio tones and test frequencies. Sine, Square, Sawtooth waves for audio testing and tinnitus relief.
White Noise Generator
Generate soothing white, pink, or brown noise for focus, sleep, and relaxation with timer controls.
WebP to JPG Converter
Convert WebP images to universally-compatible JPG format instantly in your browser.
PNG to WebP Converter
Convert PNG images to smaller WebP files with adjustable quality and transparency support.
The MP4 to MP3 Converter is maintained by CodeItBro. We aim to provide the best free developer tools on the web. If you have feedback or suggestions, please visit our contact page.
Featured on
