Pulls the audio out of a QuickTime MOV. This is usually an iPhone recording, and it works even though a browser cannot decode iPhone video — because the video track is discarded before anything tries.
Why HEVC is not a problem here
It converts anyway. Extracting audio means locating the audio track in the container and decoding only that; the video track is discarded untouched. The audio is AAC, which every browser decodes.
This is a real advantage of a demux-first design over one that decodes the whole file to convert it.
ProRes and other professional codecs
How MP3 encoding works without a server
It is the same encoder desktop software has used for twenty years, producing standard files that play everywhere. Because it is fetched on demand, pages that convert to WAV or M4A never download it.
Formats a browser genuinely cannot read
WMA (Windows Media Audio), AC-3 and DTS (cinema surround tracks), AMR (old phone voice recordings) and RealAudio are not decodable by any browser. If your file uses one you are told which, rather than being left with a failure that says nothing.
HEVC video cannot be decoded either — but that does not matter here. Extracting audio discards the video track before anything tries to decode it, so an iPhone recording converts perfectly well even though the browser could not play its picture.
Other names for this
Also searched as “quicktime to mp3”, “iphone video to mp3”, “extract audio from mov”.
Questions
- My MOV will not play in the browser but converts fine. Why?
- Playing needs the video decoded; converting to MP3 does not. The video track is discarded before decoding, so its codec is irrelevant.
- Does it work with Final Cut exports?
- Yes. ProRes video is discarded and the PCM audio converts cleanly — in fact better than most sources, since it is lossless to begin with.
- Is my file uploaded?
- No. The demuxing, decoding and encoding all happen in this tab using the browser’s own media stack plus a WebAssembly encoder. A recording can be an interview, a lecture, a private call — none of it is transmitted. Turn your Wi-Fi off after the page loads and it still works.
- How large a file can I convert?
- There is no imposed limit, only your device’s memory — around 2 GB in a desktop browser and 400 MB on a phone, since the file is held in memory while it converts. A two-hour video converts in well under a minute on a laptop.
- Can I convert several files at once?
- Yes. Drop as many as you like, or a whole folder. Each keeps its original name with the new extension, and you can download them individually or as a ZIP.