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MP3 to AAC - Online Audio Converter
Convert MP3 to AAC online. Private, client-side - no uploadrequired. Batch conversion, quality presets, codec control.
Convert MP3 to AAC
Drop MP3 audio here or click to select
MP3
AAC (AAC)
About MP3 to AAC
Convert MP3 to AAC. MP3 is the MPEG-1 Layer III codec, playable on virtually every device. AAC is the MPEG-4 successor to MP3 used by YouTube and Apple Music. Container variants (ADTS, MP4) need matching extensions on export..
Why convert MP3 to AAC?
- Smaller files with AAC lossy compression.
- Keep quality where supported.
- Private, no upload - runs in your browser.
MP3 vs AAC
| Codec | libmp3lame | AAC |
|---|---|---|
| Compression | lossy | lossy |
| Sample behavior | Quality set by bitrate | Quality set by bitrate |
| Typical use | MP3 is the MPEG-1 Layer III codec, playable on virtually every device. | AAC is the MPEG-4 successor to MP3 used by YouTube and Apple Music. |
When not to convert MP3 to AAC
- Skip AAC for archival masters: lossy compression discards detail, so keep the MP3 original.
- Keep a master copy: repeated exports stack small losses, so archive MP3 before batch AAC shares.
Limits
Starting point: MP3 - Lossy compressed music near 128-256 kbps. Repeated re-encoding stacks artifacts; convert from the master. Container variants (ADTS, MP4) need matching extensions on export. Encode AAC (AAC) from MP3 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.
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FAQ
How do I convert MP3 to AAC?
Drop your MP3 file onto this page, choose quality and codec settings, then click Convert. The result downloads as AAC instantly. All processing runs in your browser.
What codec is used for AAC?
The default codec for AAC is AAC. You can change audio parameters in Advanced mode.
How do you store my files?
We do not store any processed audio. All conversion happens entirely in your browser using FFmpeg WASM.