Compress MP4 to MP3

MP4 files are already compressed, but MP3 can compress further at a different bitrate. The size reduction is significant for sharing, uploading, and storage.

For email attachments, 128-192kbps works well. For music sharing, use 256-320kbps. AudioUtils lets you drop your file and convert instantly. No upload to a server, no waiting.

A minute of MP4 is about 60 MB; the same minute as MP3 is roughly 1.4. Across an album or a long recording that difference decides whether it fits on a phone. Re-encoding lossy to lossy compounds artifacts. Convert once, at a high bitrate, and keep the result rather than round-tripping again.

MP4 files come from phone video, recorded webinars and lectures, downloaded clips, and screen captures. The video stream is nearly the entire file, so extracting the audio collapses a 500 MB video into a few MB — which is the whole reason this conversion exists. MP3 is the destination because it plays essentially everywhere — downloads and every ordinary phone, browser, and player. Expect roughly 43× smaller: MP4 runs about 60 MB per minute, MP3 about 1.4. Both MP4 and MP3 are lossy, so this pair stacks a second encode — at a generous bitrate it stays inaudible, but if a lossless original of the MP4 exists, encode the MP3 from that instead.