Are large video files uploaded to remote servers?

Never. Processing executes entirely inside your browser sandbox via WebAssembly. Zero bytes leave your machine.

What is the audio quality of the extracted MP3?

NanoPix encodes pristine stereo MP3 audio, faithfully preserving the acoustic dynamics of your source video.

MP4→MP3100% On-Device

MP4 to MP3 Audio Converter

Lightning-Fast On-Device Extraction · Zero Uploads · Free Forever

Why Convert MP4 to MP3 Locally?

Converting music videos, podcasts, and lecture recordings into compact MP3s frees up massive storage space and allows offline listening on the go. NanoPix strips audio packets locally in seconds, completely avoiding cloud upload queues and data privacy leaks.

How to Convert MP4 to MP3

Extract MP3 audio from MP4 videos in 3 simple steps.

1Import your MP4 video file.
2Verify audio settings and choose MP3.
3Click export to extract and download your audio locally.

Frequently Asked Questions

Are large video files uploaded to remote servers?: Never. Processing executes entirely inside your browser sandbox via WebAssembly. Zero bytes leave your machine.
What is the audio quality of the extracted MP3?: NanoPix encodes pristine stereo MP3 audio, faithfully preserving the acoustic dynamics of your source video.