Convert MP3 files to AAC free in your browser — no signup, no install, and the file is never uploaded to a server.
Add your MP3 file
Drag the MP3 file onto the drop area above, or click it to pick a file from your device. You can add several files at once.
Confirm AAC as the output
AAC is already selected as the output format on this page. You can pick the bitrate — higher keeps more of the sound, lower makes a smaller file.
Run the conversion
Press the convert button. Audio decodes and re-encodes in your browser — a normal song finishes in a few seconds.
Download the AAC file
When it finishes, download the AAC file. Converting multiple files gives you the option to download them together as a ZIP.
The most widely used lossy audio format, discarding sound humans barely perceive to shrink files roughly tenfold. It is hard to find a device that cannot play it.
A lossy format designed as MP3's successor, delivering better quality at the same file size. It is the default for iTunes, YouTube, and streaming services.
Yes. MP3 to AAC conversion is completely free with no signup, no watermark, and no daily limit on the free plan for ordinary use.
No. The conversion runs entirely inside your browser using WebAssembly, so the MP3 file never leaves your device. That is also why it works without an internet connection once the page has loaded.
The free plan handles files up to 200MB. Because processing happens on your own device, very large files depend on your computer's memory rather than a server quota.
Audio converter
What each file format is, what it is used for, and which formats it can be converted to.
Open converter Browse the full format reference