MP4 to MP3 Converter
Extract audio from any video file and save it as a high-quality MP3. Supports MP4, MOV, AVI, MKV, and more. No upload — conversion runs entirely in your browser.
Drop your video file here
MP4, MOV, AVI, MKV, WebM — up to 500 MB
Browse fileHow MP4 to MP3 Conversion Works
- 1Drop or select your video file. The tool accepts MP4, MOV, AVI, MKV, WebM, and other common video formats up to 500 MB.
- 2Choose your audio quality. Select 128, 192, or 320 kbps depending on whether you prioritise file size or audio fidelity.
- 3Convert. FFmpeg runs in your browser via WebAssembly, stripping the video stream and encoding the audio as a standard 44.1 kHz stereo MP3.
- 4Preview and download. Play the extracted audio directly in your browser before saving — the download is a standard
.mp3file.
What Is FFmpeg and Why Use It?
FFmpeg is the industry-standard open-source toolkit for encoding, decoding, and converting audio and video. It powers YouTube, VLC, Handbrake, and thousands of other applications. This tool runs FFmpeg compiled to WebAssembly (WASM), which means the full conversion engine executes directly in your browser — with no server involved and no privacy risk. The output is byte-for-byte equivalent to what a desktop FFmpeg installation would produce.
Tips for Better Audio Extraction
Match bitrate to source quality
If the original video audio is compressed at 128 kbps, choosing 320 kbps output will not improve quality — it will only increase file size. Match the output to the source.
Use 192 kbps for music
192 kbps is transparent for most music when using the MP3 codec. Most listeners cannot reliably distinguish 192 kbps from 320 kbps in a blind test.
128 kbps is fine for voice
Podcasts, lectures, interviews, and audiobooks do not benefit from high bitrates. 128 kbps halves the file size compared to 320 kbps with no audible difference for speech.
Close other tabs for large files
Large video files (over 100 MB) require significant RAM and CPU. Closing other browser tabs frees memory and can speed up conversion noticeably on mid-range devices.
Preview before downloading
The built-in audio player lets you check the output before saving. Seek through the audio to confirm the full track converted correctly, not just the first few seconds.
Add metadata after conversion
The tool does not copy video metadata to the MP3. Use a free tagger like mp3tag (Windows/Mac) or MusicBrainz Picard to add artist, title, and album art after download.
Frequently Asked Questions
Is my video uploaded to a server?
No. The conversion runs entirely in your browser using WebAssembly (FFmpeg.wasm). Your video file never leaves your device — no server, no cloud, no data transfer. This also means the tool works offline once the conversion engine has loaded.
Which video formats are supported?
The tool accepts MP4, MOV, AVI, MKV, WebM, M4V, FLV, and WMV files — any format that FFmpeg can decode. The output is always a standard MP3 file compatible with all music players, phones, and streaming apps.
Why does it take a moment to start the first conversion?
The first conversion loads the FFmpeg WebAssembly engine (~10 MB) from a CDN. This takes 5–15 seconds depending on your connection. Subsequent conversions in the same session load instantly because the engine is already in memory.
What bitrate should I choose?
128 kbps is sufficient for speech, podcasts, and voice recordings where file size matters. 192 kbps is the sweet spot for music — transparent quality at a reasonable size. 320 kbps is the maximum standard MP3 quality, indistinguishable from CD audio to most listeners. If the source video has low-quality audio, higher bitrates will not improve it.
Is there a file size limit?
The tool accepts files up to 500 MB. Very large files (over 200 MB) may take several minutes to convert depending on your device's CPU speed, since the conversion runs locally in your browser.
Can I convert YouTube videos?
You can convert any MP4 file you have downloaded locally. To extract audio from a YouTube video, you would first need to download the video file to your device using a separate tool. The MP4 to MP3 converter then handles the audio extraction.
Does the output include album art or metadata?
The tool extracts the raw audio stream and does not copy video metadata such as title or thumbnails. The resulting MP3 file will not have embedded album art. You can add metadata afterward using a music tagging app like MusicBrainz Picard or mp3tag.