Convert MP4 to MP3 Online
Extract MP3 audio from a MP4 video directly in your browser. Free, no signup, and your file is never uploaded.
Click to upload or drag a file here
Supported: MP4 · Processed entirely in your browser
Converted entirely in your browser using a WebAssembly build of FFmpeg — your file is never uploaded anywhere. Larger files take longer and use more memory.
MP4 to MP3 pulls the audio track out of an MP4 video and saves it as a standalone MP3 file — one of the most common conversions people need, whether it's a soundtrack, a voiceover or a recorded call worth keeping as audio alone.
What actually happens when you extract MP3 audio from an MP4 video?
The conversion separates the audio track from the video track already stored inside the MP4 container and re-encodes it as a standalone MP3 file — you end up with just the sound, at a fraction of the original video's file size, since you're no longer storing any picture data at all.
Does extracting the audio lose any quality?
MP3 is a compressed, "lossy" format, so converting to it does involve some quality loss compared to the original audio — in practice it's rarely noticeable for speech, podcasts or casual listening, though someone doing serious audio editing might prefer extracting to an uncompressed format like WAV instead.
Is this private, and does the video get uploaded anywhere?
No — the whole conversion happens directly in your browser, so the video file is never uploaded to a server; it's also free, with no sign-up and no limit on how many files you convert.
Where did the MP3 format itself actually come from?
It was invented in Erlangen, Germany, by a small team at the Fraunhofer Institute led by Karlheinz Brandenburg, working through the late 1980s and early 1990s on a research project aimed at compressing audio for digital broadcasting. The format was technically finished by 1992, but it sat mostly unused for years — the real breakthrough wasn't the compression algorithm, but Winamp, a free MP3 player released in 1997 that finally made playing MP3s on a home computer easy, kicking off the format's explosive popularity almost five years after Brandenburg's team had already perfected it.
Is MP4 to MP3 free to use?
Yes. MP4 to MP3 is completely free, with no sign-up and no usage limits.
Do I need to install any software?
No. MP4 to MP3 runs directly in your web browser — nothing to download or install.
Is my data kept private?
Everything happens on your device. We never receive or store the file or text you enter into MP4 to MP3.