AAC to FLAC Audio Converter
Drop your AAC files — the FLAC audio is generated in your browser in seconds. Multiple files at once, no upload on the fast path.
9,214+ audio files converted
FLAC is a popular target for a reason: it is best for Archival lossless. This converter encodes straight to FLAC in your browser, so even large libraries convert quickly and privately — nothing is sent to a server on the fast path.
Looking to programmatically convert AAC to FLAC?
Same engine, available as a JSON API. Drop a file or URL via REST and get the converted audio back — no browser, no UI, no rate limits on paid tiers.
Fast response on common audio pairs
Webhook delivery for batch jobs
Dozens of audio format pairs supported
AAC vs FLAC: how they compare
The numbers and capabilities at a glance, so you know what you're trading.
AAC
- Year released
- 1997
- Compression
- Lossy
- Lossless
- No
- Channels
- Multichannel
- Player support
- Universal
- Best for
- Streaming & mobile
FLAC
- Year released
- 2001
- Compression
- Lossless
- Lossless
- Yes
- Channels
- Multichannel
- Player support
- Wide
- Best for
- Archival lossless
Heads up before converting to FLAC
What this specific conversion changes about your audio.
FLAC will not improve your AAC audio
Going from lossy AAC to lossless FLAC cannot recover detail that AAC already discarded. You get a much larger file with the same audible quality. This only makes sense for editing or archiving workflows that need a lossless container.
Best practices for FLAC
Small choices that keep your output sounding right.
- Play the first converted file before batch-converting the rest, so you catch a wrong setting early.
- FLAC is lossless — ideal for editing or archiving. Expect files several times larger than an MP3 or AAC equivalent.
- Check that title, artist, album and cover art survived the conversion; some players cache old tags.
When NOT to convert to FLAC
Cases where a different format serves you better.
When the file must play on older devices
FLAC is not supported everywhere (Wide). For old phones, car stereos, or legacy software, MP3 or AAC is a safer choice than FLAC.
The importance of a good audio conversion
Why getting AAC → FLAC right matters more than you think.
Frequently asked
The basics everyone asks before dropping a track.
Convert AAC to other formats
Convert other formats to FLAC