Convert AAC to FLAC
Free online AAC to FLAC converter that runs in your browser. Your files stay on your device.
How to convert AAC to FLAC
- Add your AAC file. Drag it onto the box above, click to browse, or paste it from the clipboard. Multiple files are fine.
- Check the target. FLAC is preselected. Pick High, Medium or Small quality depending on whether you need a master copy or a small file.
- Download. The conversion engine loads once (32 MB) and then your file is processed locally. The FLAC file downloads automatically when it is done.
Why convert AAC to FLAC?
AAC files are not supported everywhere. Converting to FLAC keeps the audio lossless while roughly halving the size.
AAC vs FLAC
| AAC | FLAC | |
|---|---|---|
| Full name | Advanced Audio Coding | Free Lossless Audio Codec |
| Type | Audio | Audio |
| MIME type | audio/aac | audio/flac |
| About | AAC is the successor to MP3, used by YouTube, Apple and most streaming services. Raw .aac streams are less portable than M4A. | FLAC is lossless compression that shrinks WAV by about half with identical quality. The standard for hi-res music collections. |
What makes this converter different
- Nothing is uploaded. Other converters send your file to a server, queue it, and keep a copy for hours. Here the work happens in your browser with WebAssembly, so private videos, voice memos and documents never leave your computer.
- No limits, no sign-up, no watermark. There is no server to pay for, so there is no reason to cap file size or count.
- Real ffmpeg quality. Video and audio use the same ffmpeg encoders professionals use (x264, LAME, libvpx, FLAC), not a stripped-down web codec.
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Frequently asked questions
Is it safe to convert AAC to FLAC here?
Yes. The conversion runs entirely inside your browser using WebAssembly. Your file is never uploaded to a server, so nothing can leak, be stored or be seen by anyone. You can even disconnect from the internet after the page loads.
How long does AAC to FLAC conversion take?
Audio converts at roughly 20–50× real time, so a 5-minute song takes about 10 seconds after the one-time engine download.
Is there a file size limit?
There is no server-side limit because there is no server. The practical limit is your device memory: browsers can handle files up to about 2 GB. Very large videos work better on a desktop than a phone.
Will the quality drop?
FLAC is lossless, so no quality is lost relative to the source. It cannot recover detail that a lossy source already discarded.
Can I convert several AAC files at once?
Yes. Drop or select as many files as you like; they are converted one after another and each gets its own download button.