Convert AAC to FLAC
Convert AAC to FLAC right in your browser — free, private, nothing is uploaded. Get a lossless file any editor opens — no further quality loss.
Convert AAC to FLAC →Free · Private — runs in your browser, nothing is uploaded
AAC is the codec behind M4A files, streaming services and much of broadcast audio; as a bare .aac stream it carries the same lossy audio without the MPEG-4 wrapper — and without proper tag support.
FLAC compresses audio without losing anything — a perfect, bit-for-bit copy at a fraction of the WAV size, which makes it the default choice for archiving music.
Converting AAC to FLAC is about compatibility rather than quality: some editors, DAWs and pipelines simply insist on FLAC. You get a file they open natively — but the audio can never get better than the AAC you start from.
AAC vs FLAC
| AAC | FLAC | |
|---|---|---|
| Compression | lossy — some detail traded for size | lossless — nothing discarded |
| Codec / container | raw AAC (Advanced Audio Coding) stream | Free Lossless Audio Codec |
| Typical file size | small — similar to MP3 at the same bitrate | medium — typically 50–70% of the equivalent WAV |
| Best for | streams, broadcast audio and recorder output | archiving and lossless music libraries |
| Strength | modern lossy codec, efficient at every bitrate | lossless and compressed — a perfect copy, smaller than WAV |
| Watch out for | bare .aac streams carry no metadata and trip up some players | much larger than lossy formats; some older hardware skips it |
| Compatibility | the codec is everywhere, but fewer apps open bare .aac files | wide in modern software; patchy on older hardware players |
How the conversion works
- Choose your AAC file (up to 10 MiB). The button above opens the converter with FLAC already selected as the target format.
- There is no bitrate to choose: FLAC is lossless, so the bitrate field is simply ignored.
- Run the conversion and download the result — the output keeps your filename with a .flac extension. Everything happens locally: the page runs ffmpeg compiled to WebAssembly, so your audio is never uploaded to a server.
What to expect
No quality is restored. FLAC preserves exactly what's in your AAC file — detail the AAC encoder already discarded is gone for good. Expect a much larger file with identical sound; convert because a tool needs FLAC, not to upgrade the audio.
Embedded album art is dropped along the way: cover images ride along as a video stream, which audio-only outputs like FLAC can't carry.
FAQ
Does converting AAC to FLAC improve the audio quality?
No. FLAC preserves exactly what's in the source — detail the AAC encoder already discarded is gone for good. Convert because a tool needs FLAC, not to upgrade the sound.
Why is the FLAC file so much larger than my AAC?
AAC stores heavily compressed audio; FLAC stores a losslessly-compressed copy of the decoded audio — so the same sound takes several times the space. That's normal, and the extra bytes don't add quality.
Is my AAC file uploaded when converting to FLAC?
No. The page downloads an ffmpeg WebAssembly build once, then converts your file locally in the browser tab — the audio never leaves your device. Input files up to 10 MiB are supported.