Converting AAC to FLAC wraps the decoded audio in a lossless compressor. The operation preserves whatever the AAC decoded to, adds better tagging and verification, and normalizes your library format. It does not recover any quality the AAC encoder discarded.
Drag & drop audio files here, or browse
Drop your AAC files here
No audio change. The FLAC will be larger than the AAC (lossless compression of already-lossy audio still produces bigger files than the original lossy encode) in exchange for universal lossless-library tooling support.
FLAC plays on Windows, macOS, Linux, Android, modern iOS, and every major player. It's widely supported by library and streaming software.
AAC is the successor the MPEG group designed to replace MP3. At 128 kbps it typically sounds as good as MP3 at 192 kbps. It's the default codec for YouTube audio, iTunes purchases, Apple Music, and nearly every streaming service that isn't using Opus or Vorbis.
FLAC is a lossless compressor: it shrinks PCM audio to roughly 50–60% of its original size and decodes back to a bit-perfect copy. It supports tags, cue sheets, and up to 32-bit / 655 kHz, which makes it the de facto format for CD rips and audiophile music libraries.
No. FLAC is a lossless container, but it can only preserve whatever audio it's given. If you feed it the output of a lossy AAC decoder, the FLAC preserves that lossy audio exactly.
FLAC stores full PCM compressed losslessly, while AAC aggressively throws away data to get smaller. A typical FLAC is 4–5× the size of an equivalent-duration AAC.
AAC is the successor the MPEG group designed to replace MP3. At 128 kbps it typically sounds as good as MP3 at 192 kbps. It's the default codec for YouTube audio, iTunes purchases, Apple Music, and nearly every streaming service that isn't using Opus or Vorbis.
FLAC is a lossless compressor: it shrinks PCM audio to roughly 50–60% of its original size and decodes back to a bit-perfect copy. It supports tags, cue sheets, and up to 32-bit / 655 kHz, which makes it the de facto format for CD rips and audiophile music libraries.
Yes. The converter runs entirely in your browser using FFmpeg compiled to WebAssembly. Your audio files are never uploaded, never sent to a server, and never leave your device.
There's no hard limit, but because everything runs in your browser you're bounded by available memory. Files over about 2 GB total can get slow or hit browser memory limits. Process in smaller batches if you run into issues.