RaahUPSC · Audio Tools
AAC to FLAC Converter
Decode .aac files and store the result as FLAC, a lossless compressed format that is smaller than WAV and supports tags. Useful when an archive, editor or player insists on FLAC.
✓ No upload · ✓ No sign-up · ✓ No watermark
How to use AAC to FLAC Converter
- Add your .aac files to the drop area.
- Play the first one in the preview if needed.
- Press Convert to FLAC.
- Download the FLAC files individually or as a ZIP.
What AAC to FLAC can and cannot do
FFmpeg decodes the AAC stream and passes the samples to its native FLAC encoder at its default compression level. FLAC is lossless, so the output is a bit-exact copy of the decoded audio, typically about half to two-thirds the size of an equivalent WAV.
The catch: AAC is lossy, and whatever it discarded is gone. A FLAC made from AAC is not 'hi-res' and will be several times larger than the source. Choose it to freeze the audio for editing or archiving, or to meet a FLAC-only requirement, not to improve sound.
Limitations
- The FLAC will be much larger than the AAC while sounding the same.
- No setting exists for FLAC compression level or bit depth.
- Music sites and audio checkers can detect FLAC files that came from a lossy source.
Frequently asked questions
Will FLAC make my AAC sound better?
No. FLAC preserves exactly what it is given. Since the AAC already lost some detail, the FLAC simply locks in the current quality.
Why choose FLAC over WAV?
FLAC is compressed without loss, so it is noticeably smaller than WAV and supports proper metadata tags.
Do my files get uploaded?
No. The FLAC encoding is performed by FFmpeg running in this browser tab.