Free MP4 to MP3 Converter — Extract Audio Online, No Limit
Convert MP4 to MP3 online for free — no signup, no file size limit, no install. Extract audio from any MP4 video in seconds, right in your browser using FFmpeg WebAssembly.
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.
Extract Audio from Any MP4 Video — Instantly
Need just the audio from a video? Our free MP4 to MP3 converter strips the video track and gives you a clean, high-quality MP3 file. No upload, no account, no watermark — everything is processed locally in your browser using FFmpeg WebAssembly. Works with MP4, WebM, MOV, and most other common video formats.
Key Features
Selectable Bitrate (128–320 kbps)
Choose from 128, 192, 256, or 320 kbps to balance file size and audio quality for your use case.
Works with MP4, WebM, MOV & More
Accepts most common video container formats — if it plays in a modern browser, it converts.
Completely Private
Your video never leaves your device. No uploads, no cloud processing, no data collection.
Audio Preview Before Download
Listen to the extracted MP3 in the built-in player before saving — confirm quality before committing.
Common Use Cases
Podcasts & Talks
Convert video podcast episodes to audio-only MP3 for distribution on podcast platforms
Music & Soundtracks
Save the audio track from a music video for offline listening on any device or media player
Lectures & Courses
Turn recorded video lectures into lightweight MP3 files for studying and listening on the go
Bitrate Guide: Which Setting to Choose
Compact file size, perfectly clear for voice content. A 1-hour lecture converts to ~55 MB.
The best all-around balance of quality and file size. ~82 MB per hour of audio.
Near-transparent quality. Suitable for music archiving where file size is less of a concern.
The highest MP3 bitrate, essentially indistinguishable from lossless for most listeners. ~138 MB/hour.
How this Free MP4 to MP3 Converter — Extract Audio Online, No Limit works
How the conversion works
When you click Convert, the tool loads FFmpeg's single-threaded WebAssembly core, reads your MP4 into a virtual filesystem, and runs an audio extraction pass: the video stream is stripped with -vn and the audio is re-encoded as MP3 using libmp3lame at your chosen bitrate (128, 192, 256, or 320 kbps) and 44.1 kHz stereo output.
Choosing the right bitrate
128 kbps — compact and perfectly clear for speech, podcasts, and lecture recordings. 192 kbps — the go-to balance for general music and mixed content. 256–320 kbps — near-CD quality, ideal when preserving full audio detail from a music video matters most.
Expected file sizes
A one-hour MP4 lecture (~600 MB at 1080p) typically converts to about 55 MB at 128 kbps or 110 MB at 256 kbps. Audio-only files are far smaller than their source videos because the video track is removed entirely.
Privacy and offline use
Your video file is never transmitted anywhere. Once the WebAssembly engine has loaded, you can convert MP4 to MP3 offline in Chrome or Edge without an internet connection. No tracking, no ads injected into the output, no file size cap enforced by the tool.
How to use this Free MP4 to MP3 Converter — Extract Audio Online, No Limit
Upload your MP4 video
Drag and drop or click to select an MP4 video file from your device. Most video formats are accepted.
Choose output bitrate
Select 128 kbps for speech and podcasts, 192 kbps for music, or 256–320 kbps for highest quality.
Convert and download
Click Convert to extract the audio track. Preview it in the browser, then download your MP3 file.
Example Usage
A 45-minute lecture video shrinks from 120 MB to 42 MB after audio extraction — perfect for listening on the go.
Frequently Asked Questions
How do I convert MP4 to MP3 for free with no limit?
What bitrate should I choose for MP3 output?
Is there a file size limit?
Is my video file safe and private?
What video formats can I convert besides MP4?
Why is my conversion slow on large files?
Related Tools
WAV to MP3 Converter
Convert WAV files to MP3 format instantly. Compress large audio files for easier sharing and streaming.
MP4 to GIF Converter
Convert MP4 videos to animated GIFs directly in your browser. Set frame rate, output width, and clip start/end time — no upload required.
MOV to MP3 Converter
Extract audio from Apple MOV videos and save as MP3 with selectable bitrate.
M4A to MP3 Converter
Convert Apple M4A audio files to universally compatible MP3 with bitrate control.
MP4 Compressor
Compress MP4 videos online. Reduce file size while maintaining quality options.
Video to MP3 Converter
Extract high-quality MP3 audio from any video file instantly in your browser.
The Free MP4 to MP3 Converter — Extract Audio Online, No Limit 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.
As featured on
