Change MP3 audio to AAC for any player or device, with the bitrate, sample rate and channels you choose. Free, with no upload.
Drop audio or video files here
or paste them, or click to choose — several files at once
Choose filesMP3, WAV, FLAC, OGG, M4A, AAC, OPUS, AIFF, WMA, APE, AMR, MP4 and more · up to 300 MB per file
The converter (about 30 MB) is downloaded once on first use and then cached. Your files never leave your device.
Drop MP3 files onto the converter, paste them, or click to choose. You can add many at once.
AAC is already selected. If you like, adjust the quality, sample rate or channels before or after adding files.
Each file is converted in your browser in seconds. Save them one by one, or all at once as a ZIP.
MPEG-1 Audio Layer III
The universal audio format
MP3 is the most widely supported compressed audio format. It removes sounds the ear barely notices, shrinking music to about a tenth of its CD size.
Advanced Audio Coding
Efficient successor to MP3
AAC (Advanced Audio Coding) was designed to replace MP3 and is used by YouTube, Apple and digital radio. An .aac file is a raw AAC stream without an MP4 container.
Audio is converted by ffmpeg running inside your browser. Your files never reach a server.
Queue up to 50 files and download them one by one or together as a ZIP.
Set the bitrate, bit depth, sample rate and channels — or simply keep the sensible defaults.
Add your MP3 files to the converter above. AAC is already selected as the output, so conversion starts right away. When a file is ready, click Download, or use Download all to get a ZIP.
Both formats are lossy, so re-encoding adds a little loss. Choose a bitrate equal to or higher than the original (for example 192–256 kbps) and the difference will be inaudible.
192 kbps is transparent for most music and 128 kbps is plenty for speech. Choose M4A instead if you want cover art and tags to be kept.
No. The MP3 to AAC conversion runs entirely in your browser using ffmpeg compiled to WebAssembly. Your files are never sent to a server, so even private recordings stay on your device.
Yes. Add up to 50 files; they are converted one after another, and you can download each AAC file separately or all of them together as a ZIP archive.