Convert MP3 to AAC
Re-encode an MP3 as raw AAC for workflows that specifically ask for it. The conversion runs in your browser, so your audio is never uploaded.
Why convert MP3 to AAC?
Most people never need to leave MP3, but some pipelines are strict about format. Broadcast and radio ingest systems, some streaming upload tools, and certain car head units and Android players expect AAC, and a few specifically want a raw .aac stream rather than an M4A. Convert when a platform rejects your MP3 or a spec sheet names AAC. If you only need something that plays everywhere, keep the MP3, because it already does.
Quality and file size
Both formats are lossy, so this is a transcode: the MP3 is decoded and re-encoded as AAC, adding a little generation loss on top of what the MP3 already discarded. AAC is more efficient than MP3, but it cannot restore detail the MP3 threw away, so do not expect the result to sound better than the source. Choose 256 or 320 kbps to keep the extra loss inaudible. If you still have the original WAV or FLAC, convert from that instead for a cleaner AAC.
MP3 to AAC: common questions
Will converting MP3 to AAC improve the sound?
No. AAC is a more efficient codec, but it can only work with what the MP3 kept. Re-encoding adds a small amount of loss rather than removing any. Convert for compatibility, not for quality.
Is my file uploaded anywhere?
No. The conversion runs entirely in your browser with FFmpeg compiled to WebAssembly. Your file never leaves your device, and we never see it, store it, or train on it.
What is the difference between AAC and M4A?
AAC is the audio codec. M4A is an MP4 container that usually holds AAC audio plus tags and cover art. A raw .aac file is the same kind of audio without that container, so it carries far less metadata. Pick M4A unless something specifically asks for .aac.
What bitrate should I choose?
Use 256 or 320 kbps so the second encode stays transparent. Lower bitrates save space but, stacked on an MP3's existing loss, start to show artifacts on cymbals and vocals.
Who makes this?
We're the small team behind Xport Studio, a private, fully offline app for AI vocals, stems, and mastering. These free tools are side experiments we wanted to share. No upsell, but if you're curious about the bigger thing, take a look.