Convert FLAC to MP3
Your lossless library, everywhere — converted to high-quality MP3 on your own machine, one album-sized fraction of the space.
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 the collector's format: perfect lossless copies of your music, beloved by archivists and audiophiles — and unplayable on a surprising number of car stereos, older phones, portable players, and apps. MP3 at high quality plays on all of them and takes roughly a third of the space, which is why FLAC-to-MP3 remains one of the most common audio conversions there is.
ConvertUno decodes your FLAC and re-encodes it at high quality entirely on your device — an entire album converts without a single byte uploading anywhere. Keep the FLAC as your archive master; carry the MP3 in your pocket.
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 quality do I lose going FLAC to MP3?
At high-quality encoding, less than almost anyone can hear in normal listening — double-blind tests consistently show high-bitrate MP3 is transparent for the vast majority of listeners and material. Your FLAC remains untouched as the perfect master.
How much smaller is the MP3?
Typically 60–70% smaller — a 40 MB FLAC track becomes roughly a 10–14 MB MP3, and a full album fits where two FLAC tracks used to.
Can I convert an entire album?
Yes — select the whole album at once and the tracks convert one after another on your device, each in seconds since nothing uploads, with a download-all button at the end.
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.