FLAC to AAC - Online Audio Converter
Convert FLAC to AAC online. Private, client-side - no uploadrequired. Batch conversion, quality presets, codec control.
About FLAC to AAC
FLAC halves WAV sizes bit-for-bit with open hardware support, which suits archiving. AAC re-encodes the decoded sound with the MPEG-4 successor codec for streaming services and Apple hardware. Decoding restores exact samples first, so only the AAC pass discards detail. Use 256k for music and 128k for speech. Apple players prefer AAC over FLAC for phone libraries, which makes this path useful before syncing. Keep the FLAC master for future re-exports.
Why convert FLAC to AAC?
- Smaller files with AAC lossy compression.
- Keep quality where supported.
- Private, no upload - runs in your browser.
FLAC vs AAC
| Codec | FLAC | AAC |
|---|---|---|
| Compression | lossless | lossy |
| Sample behavior | Full quality kept | Quality set by bitrate |
| Typical use | FLAC halves WAV sizes bit-for-bit with open hardware support. | AAC is the MPEG-4 successor to MP3 used by YouTube and Apple Music. |
When not to convert FLAC to AAC
- Skip AAC for archival masters: lossy compression discards detail, so keep the FLAC original.
- Keep a master copy: repeated exports stack small losses, so archive FLAC before batch AAC shares.
Limits
Starting point: FLAC - Bit-identical compression near half the WAV size. Apple players prefer ALAC; convert for iPhone libraries. Container variants (ADTS, MP4) need matching extensions on export. Encode AAC (AAC) from FLAC at 256k for music or 128k for speech, starting from the master.
How conversion works
Conversion runs entirely in your browser with FFmpeg WASM. Files never leave your device.