Convert MP3 to AAC
Free online converter for MP3 files. Efficient successor to MP3 used in broadcast and streaming. Nothing to install, no watermark, and every file is deleted automatically.
Drag and drop your files
or
Upload a MP3 file to convert it to AAC. Up to 3 files at once, 100 MB each.
Free · up to 3 files · 100 MB each · files deleted automatically after 1 hour.
About MP3 and AAC
MP3 .mp3
The format that made digital music portable. Lossy, thirty years old, and still the safest choice when you have no idea what will play the file.
Good for
- Plays on essentially every device ever made
- Small files at listenable quality
- Patents long expired, so support is everywhere
Trade-offs
- Lossy — detail is gone permanently
- Beaten by AAC and Opus at the same bitrate
- No transparency about what was discarded
audio/mpeg
AAC .aac
MP3's designated successor, and the default in the Apple ecosystem and most streaming services. Better sound than MP3 at the same bitrate.
Good for
- Noticeably better than MP3 at equal bitrates
- The default across Apple devices and most streaming
- Handles multichannel audio properly
Trade-offs
- Lossy
- Patent licensing is more involved than Opus or Vorbis
audio/aac
MP3 and AAC side by side
| MP3 | AAC | |
|---|---|---|
| Compression | Lossy | Lossy |
| Typically used for | Music, podcasts, anything that must simply play | Streaming, Apple devices, video soundtracks |
What changes when you convert MP3 to AAC
This is a re-encode, not a repackage
Some tools can move a stream into a different container untouched when the codecs happen to line up. We do not — every job here is decoded and encoded again, so the conversion takes time in proportion to the length of the file and costs a small amount of quality even where a repackage would have been possible. In exchange the output is predictable: it plays everywhere, rather than inheriting whatever the source happened to contain.
What your AAC will contain
The output is AAC — at 192 kbps, written as a raw ADTS stream rather than wrapped in a container. AAC is meaningfully better than MP3 at the same bitrate, which is why it became the default for streaming and broadcast. If you want tags and artwork to travel with it, choose M4A instead — the same audio in a container that has somewhere to put them.
Re-encoding costs a little quality
Both formats are lossy, so this decodes MP3 and compresses again as AAC. That second pass loses a small amount on top of what was already gone. It is barely audible once, and it accumulates if a file is converted repeatedly — so convert from the original rather than from a previous conversion.