Convert MP3 to FLAC
Free MP3 to FLAC converter that runs entirely in your browser. No uploads, no signup required.
Drop MP3 files here
or browse your device. Free, no signup required, no watermarks.
Files are processed on your device, never uploaded
Media conversions run on a full FFmpeg engine compiled to WebAssembly. The engine (~31 MB) downloads once on your first conversion, then everything runs locally.
Three steps
How to convert MP3 to FLAC
Add your files
Drop MP3 files into the box above, or click it to browse. Add several to batch convert.
Convert
FLAC is already selected as the output. Hit Convert. Your browser does the work locally.
Download
Save each converted FLAC file. Pro ZIPs whole batches in one click.
MPEG audio layer III
MP3
MP3 is the universal audio format. It plays on every device, app, and car stereo made in the last 25 years.
Free Lossless Audio Codec
FLAC
FLAC compresses audio to about half the size of WAV with zero quality loss. It is the audiophile's archive format.
Why convert MP3 to FLAC?
MP3 is the universal audio format. It plays on every device, app, and car stereo made in the last 25 years. FLAC compresses audio to about half the size of WAV with zero quality loss. It is the audiophile's archive format. Converting from MP3 to FLAC gets you the best of the target format wherever MP3 falls short, whether that's compatibility, file size, or what your apps and devices can open. With FormatFusion the switch takes seconds and your files stay on your device the whole time.
Questions
MP3 to FLAC: common questions
Is this MP3 to FLAC converter free?
Yes. It is completely free with no watermarks and no account required, for files up to 1 GB each. Convert one file or a hundred.
Is it safe to convert MP3 files here?
Safer than any upload-based converter. The conversion runs locally in your browser, so your MP3 files are never sent over the internet and never touch a server.
Will I lose quality converting MP3 to FLAC?
No. This conversion preserves your content, and FLAC output keeps everything the format supports.
Can I convert multiple MP3 files at once?
Yes. Free converts up to three MP3 files at a time. FormatFusion Pro batches without limits and downloads whole runs as a single ZIP.
Does it work on iPhone and Android?
Yes. FormatFusion runs in any modern mobile or desktop browser. No app install needed.