AudioUtils

No upload · No server · Apple's preferred codec

AAC Converter

Convert MP3, WAV, FLAC, OGG, WMA, or AIFF to AAC -- or convert AAC to any format. FFmpeg runs in your browser, nothing is uploaded. Free.

About the AAC Format

AAC (Advanced Audio Coding) was standardized in 1997 as part of the MPEG-4 specification, designed to replace MP3 as the dominant lossy audio format. Apple adopted it as the default for iTunes and the iPod in 2003, which cemented its status as the most widely deployed audio codec after MP3.

The key advantage of AAC over MP3 is efficiency. At 128 kbps, AAC sounds significantly better than MP3 at the same bitrate. This makes AAC the right choice for streaming, mobile storage, and any situation where file size matters. Apple Music streams at 256 kbps AAC -- a setting that is transparent to virtually all listeners.

AAC is widely supported: iPhones, iPads, Macs, Android (4.1+), YouTube, Spotify, Apple Music, and most modern streaming platforms all handle AAC natively. The main caveat is that AAC is still patent-licensed, unlike the open-source OGG Vorbis or Opus codecs.

Convert AAC files without uploading them

AudioUtils runs FFmpeg as WebAssembly directly in your browser. Your AAC files -- whether they are music recordings, voice memos, podcast drafts, or unreleased tracks -- never leave your device. No servers receive your audio. No temporary files are stored remotely. No privacy policy loophole allows us to access your content, because we never receive it. Conversion speed is limited only by your CPU, not by upload bandwidth.

Frequently Asked Questions

Is this AAC converter free?

Yes. AudioUtils is free to use. The free tier outputs a 10-second preview of your converted file. Pro ($9/mo) removes the preview limit so you can convert full-length files up to 500 MB.

What formats can I convert to AAC?

You can convert MP3, WAV, FLAC, M4A, OGG, WMA, AIFF, and Opus to AAC. All conversions run entirely in your browser using FFmpeg WebAssembly -- nothing is uploaded to any server.

What is AAC and how does it differ from MP3?

AAC (Advanced Audio Coding) was designed as the successor to MP3. At the same bitrate, AAC typically sounds noticeably better than MP3 -- especially at lower bitrates like 128 kbps. AAC is the default format for iTunes, Apple Music, YouTube streaming, and most Apple devices. It is stored as .aac or .m4a files.

Is AAC the same as M4A?

AAC is the audio codec; M4A is the container format. An M4A file almost always contains AAC audio. The difference is like MP3 (codec) vs a plain .mp3 file. For most purposes, AAC and M4A are interchangeable. AudioUtils can convert to both.

What bitrate should I use for AAC?

For music: 256 kbps AAC is the Apple Music and iTunes standard -- transparent quality for most listeners. 128 kbps AAC sounds better than 128 kbps MP3 and is fine for podcasts and speech. For the best balance of quality and file size, use 192 kbps for music and 96-128 kbps for voice.