FLAC vs AAC
How do FLAC and AACcompare? Here's everything you need to know to choose the right format — and how to convert between them.
.flac
Full guide →Free Lossless Audio Codec
FLAC is the leading open-source lossless audio format. It compresses audio files to about 50-60% of their original size without any quality loss — perfect for audiophiles and music archival.
.aac
Full guide →Advanced Audio Coding
AAC is the successor to MP3, offering better sound quality at lower bitrates. It's the default audio format for Apple Music, YouTube, and most streaming platforms.
| Specification | FLAC | AAC |
|---|---|---|
| Full name | Free Lossless Audio Codec | Advanced Audio Coding |
| Extension | .flac | .aac |
| MIME type | audio/flac | audio/aac |
| Category | Audio | Audio |
| Developer | Xiph.Org Foundation | ISO / Fraunhofer / Dolby / Sony / Nokia |
| Year introduced | 2001 | 1997 |
| Compression | Lossless | Lossy |
FLAC advantages
- Lossless — identical to original audio
- 50-60% smaller than WAV
- Open source and royalty-free
- Excellent metadata and tagging support
FLAC limitations
- Larger than lossy formats like MP3
- Not supported by all portable devices
- Slower to encode than lossy formats
- iTunes/Apple Music prefer ALAC
AAC advantages
- Better quality than MP3 at same bitrate
- Default format for iTunes and Apple Music
- Widely used in streaming
- Supports up to 48 channels
AAC limitations
- Patent-encumbered
- Slightly less universal than MP3
- Encoding quality varies by implementation
- DRM can restrict usage
Which should you use?
FLAC preserves full audio quality with no compression artifacts. AAC offers much smaller files at the cost of some quality. For casual listening, AAC is fine. For production or archival, use FLAC.
Best uses for FLAC
Best uses for AAC
Convert between FLAC and AAC
Need to switch formats? Convert for free with SquishConvert.