Frequently asked questions
Is the site really free and unlimited?
Yes. No sign-up, no quota, no watermark, no paid version. The site is funded by unobtrusive advertising and, if you wish, by your donations.
Where are my files converted?
In your browser, on your device. We use FFmpeg compiled to WebAssembly. Technically, you can switch off your internet connection once the engine has loaded: the conversion will still work. If your browser does not support WebAssembly (very rare), the site falls back to server-side conversion with automatic deletion of the file after 30 minutes, and you are told about it.
Which formats are accepted?
Input: M4A, MP3, WAV, FLAC, AAC, OGG, OPUS, WMA, AIFF, WebM, plus the audio track of MP4, MOV and MKV videos. Output: MP3, M4A, WAV, FLAC, AAC, OGG, OPUS, AIFF. The full list is here.
What is the maximum file size?
200 MB per file, with no limit on the number of files. On mobile, very large files may run out of memory: prefer a computer above 100 MB.
Why is the first run slower?
The conversion engine (about 10 MB compressed) is downloaded once, then kept in your browser's cache. Subsequent conversions start instantly.
The conversion fails: what should I do?
Check that the file is not DRM-protected (iTunes purchases from before 2009, Apple Music/Spotify/Deezer downloads: they cannot be converted). Try another browser (a recent Chrome or Firefox). If the file is corrupted, VLC may be able to repair it. Otherwise, write to us with the error message.
Is my metadata (title, artist, cover art) preserved?
Yes, whenever the output format supports it (MP3, M4A, FLAC, OGG, OPUS). WAV and raw AAC have no standardized tagging system.
Can I use the site offline?
Once the engine has loaded, yes, as long as the tab stays open. An installable version (PWA) is planned.
Can I use it for professional purposes?
Yes, without restriction. Since the files stay on your machine, it is suitable for confidential recordings (interviews, consultations, meetings).
Do you collect personal data?
No. We see neither your files nor their names. Traffic statistics are anonymous and cookie-free. See the privacy policy.
How do I report a bug or suggest an improvement?
Through the contact page. Feedback is read and fixes are quick.