MP3 to FLAC
Convert MP3 audio to lossless FLAC โ right in your browser, nothing uploaded.
Drag & drop your MP3 files here, or click to choose. Everything runs in your browser — nothing is uploaded.
FLAC is a lossless audio codec: it compresses without discarding a single sample, which is why it is the standard for music archives, audiophile libraries and moving tracks between machines. Converting an MP3 to FLAC will not restore or improve quality, because MP3 already discarded data when it was first encoded - what you get instead is a stable, lossless copy that suffers no further loss if you edit or re-encode later, and playback on the many players that prefer FLAC. The trade-off is size: the FLAC will be noticeably bigger than the MP3. This converter runs entirely in your browser using a WebAssembly build of FFmpeg, so nothing is uploaded. Drop in several MP3s at once, preview each result inline, and download - free, with no signup or install.
Frequently Asked Questions
How do I convert MP3 to FLAC?
To convert MP3 to FLAC, drag your MP3 files onto the drop area on this page, or click it to browse and choose them, and conversion starts automatically the moment the files are added, with each finished FLAC appearing as its own row carrying a Download button. You can add several MP3s at once; they convert one after another, and every row shows the new filename, its size and an inline player so you can listen before downloading. It all runs in your browser through a WebAssembly build of FFmpeg, so your audio is never uploaded.
Does converting MP3 to FLAC improve the sound quality?
No, converting MP3 to FLAC cannot improve the sound quality, because MP3 is a lossy format and the detail its encoder discarded is permanently gone, so FLAC can only preserve exactly what the MP3 already contains and has no way to rebuild the audio that was thrown away. What you do gain is a lossless master from this point on, so editing or re-encoding it later adds no further generation loss. That stable, future-proof copy - not restored fidelity - is the real reason to move MP3s into FLAC.
Is this MP3 to FLAC converter free and private?
Yes, it is completely free and genuinely private, with no signup, no account, no watermark and nothing to install, and because the conversion happens inside your browser using a WebAssembly build of FFmpeg, your MP3 files never leave your device or touch a server at any point. That makes it safe for unreleased tracks, client work and other confidential audio. There is no queue and no upload wait, since all the work happens locally on your own machine.
Why would I convert MP3 to FLAC?
Convert MP3 to FLAC when you want a lossless working copy that will not degrade further, or when a player, editor or library insists on FLAC and refuses MP3, since FLAC is the open, archival standard that stores audio without discarding any of it. Keep in mind that this does not recover quality the MP3 already lost, and the FLAC will be a good deal larger. If small files matter more than a lossless archive, staying with MP3 or converting to AAC makes more sense.
How much bigger will the FLAC be than the MP3?
Expect the FLAC to be several times larger than the MP3, often five to ten times, because MP3 is a compact lossy format while FLAC stores every sample losslessly at roughly 50 to 60 percent of uncompressed WAV size, so you are trading disk space for a lossless copy. The exact ratio depends on how the source MP3 was compressed and on the music itself. A heavily compressed MP3 holds little data, yet its FLAC still balloons in size without adding any quality the MP3 never had.
Is there a file size limit for MP3 to FLAC conversion?
There is no file size limit imposed by this site, because your MP3 files are never uploaded and the only real ceiling is how much memory your own device can spare, which is usually far more generous than the caps on upload-based conversion services. Very large files, roughly a few hundred megabytes or more, can be slow or run out of memory on a phone. For long recordings or whole albums, use a desktop browser.
Does this work on iPhone, Mac and Android?
Yes, it works in any modern browser on Windows, Mac, Linux, iPhone and Android, with no app to install on any of them, because the entire conversion runs locally through a WebAssembly build of FFmpeg rather than on a remote server you have to sign in to. The first conversion downloads the roughly 32 MB converter engine, which your browser then caches so later conversions start instantly. On phones, stick to shorter files, since long recordings can exhaust mobile memory.