Convert FLAC to M4A
The listening copy of your lossless library — encoded from the master on your own device.
Drop your video or audio here
or
MP4, MOV, WebM, MKV, AVI, MP3, WAV and more — any size, no upload
🔒 Files never leave your device — everything runs in your browser.
FLAC is for keeping; M4A is for carrying. A lossless library sounds wonderful on the shelf, but phones fill up, Apple's apps want their own format, and daily listening never needs archival fidelity. Encoding M4A copies from FLAC masters is the classic keep-both-worlds move.
This is the best-case lossy encode: starting from a perfect lossless source, one clean AAC pass at high quality — transparent for normal listening at a fraction of the size. The FLAC stays untouched as your archive; the M4A goes wherever you do. Everything runs in your browser, nothing uploads.
How it works
- Drop your file
Any common format, any size. Nothing is uploaded — the tool runs in your browser.
- Convert
Compatible files are repackaged instantly with zero quality loss; others are hardware-transcoded at high quality.
- Download
Your converted file is ready on your device — nothing to wait for, nothing to delete from a server.
Frequently asked questions
How much smaller is the M4A than the FLAC?
Substantially — FLAC runs about half of uncompressed size, while AAC runs about a tenth, so expect the M4A at roughly a fifth of the FLAC. Across a music library that difference is entire albums of phone storage.
Will I hear the difference from my FLAC?
In normal listening, no — AAC at the high-quality setting used here is transparent for nearly all material and ears. The FLAC remains your reference copy whenever you want the mathematical guarantee.
Should I delete the FLAC after converting?
Keep it if you can — the FLAC is the master you re-encode from whenever formats or preferences change. The M4A is a derived copy; the archive is what protects the collection.
Is my file uploaded to a server?
No. ConvertUno runs entirely in your browser on your own device. Your file never leaves your computer or phone — there is no upload at all.
Is it really free, with no watermark?
Yes. Processing happens on your device, so serving you costs us almost nothing — no watermark, no account, no file-size limit, no daily quota.