MP3 vs AAC
How do MP3 and AACcompare? Here's everything you need to know to choose the right format — and how to convert between them.
.mp3
Full guide →MPEG Audio Layer III
MP3 is the most popular audio format in the world. It revolutionized digital music by compressing audio files to a fraction of their original size while maintaining good quality. Nearly every device and application supports MP3.
.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 | MP3 | AAC |
|---|---|---|
| Full name | MPEG Audio Layer III | Advanced Audio Coding |
| Extension | .mp3 | .aac |
| MIME type | audio/mpeg | audio/aac |
| Category | Audio | Audio |
| Developer | Fraunhofer Society / Moving Picture Experts Group | ISO / Fraunhofer / Dolby / Sony / Nokia |
| Year introduced | 1993 | 1997 |
| Compression | Lossy | Lossy |
MP3 advantages
- Universal compatibility — works everywhere
- Excellent compression ratios
- Metadata support (ID3 tags)
- Variable and constant bitrate options
MP3 limitations
- Lossy compression — some quality loss
- Not suitable for professional audio production
- Patent-encumbered (patents expired 2017)
- Inferior quality to modern codecs at same bitrate
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?
AAC offers better quality at the same bitrate — it's the modern evolution of MP3. But MP3 has unbeatable compatibility. For Apple devices, AAC is native. For everything else, MP3 is the safest bet.
Best uses for MP3
Best uses for AAC
Convert between MP3 and AAC
Need to switch formats? Convert for free with SquishConvert.