MP3 AAC

MP3 to AAC Converter

Convert MP3 to AAC in your browser. Free, private, and fast. Choose the right codec, quality, and file size without sending files to a server.

This converter runs a full FFmpeg engine in your browser. The first conversion downloads the engine (~31 MB, cached afterwards) — your file itself still never leaves your device.

Drag & drop your MP3 file here

or

Max file size: 50 MB · Your file stays in your browser

Your file is processed locally in your browser — nothing is ever uploaded.

Why Convert MP3 to AAC?

Converting MP3 to AAC is a common task whenever a file has to work somewhere that expects the other format. MP3 is the world's most widely supported audio format. AAC is the lossy audio codec designed as the successor to MP3 and delivers better quality at the same bitrate. This converter makes the switch locally in your browser — nothing is uploaded.

Common use cases

  • You have a MP3 file and need it in AAC format.
  • The target software or platform requires AAC but your file is in MP3.
  • Typical use of AAC: Smaller music files than MP3 at the same quality.
  • You want to reduce file size or improve compatibility without using desktop software.
Keep in mind: Raw AAC files carry little metadata such as cover art or tags; M4A is better for music libraries.

How to Convert MP3 to AAC

  1. Upload or drop your MP3 file into the converter above.
  2. Adjust any output settings for AAC if needed.
  3. Click Convert and download your converted file instantly.

About the Formats

MP3 (MPEG Audio Layer III)

MP3 is the world's most widely supported audio format. Introduced in 1993, it uses psychoacoustic compression to dramatically reduce file sizes while preserving perceptible audio quality.

Compatibility: Universal — supported by every device, browser, media player, and platform.

AAC (Advanced Audio Coding)

AAC is the lossy audio codec designed as the successor to MP3 and delivers better quality at the same bitrate. Raw .aac files hold the audio stream on its own, while the same audio usually lives inside an M4A or MP4 container.

Compatibility: Supported by iOS, Android, Windows, macOS, browsers and nearly all current players.

100% Private & Browser-Based

Your files never leave your device. All conversion happens locally in your browser — nothing is uploaded to any server. No sign-up required.

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Need the reverse?

AAC to MP3 Converter

FAQ

Frequently Asked Questions

Yes — completely free with no sign-up, no watermarks, and no size limits for typical files.

Quality depends on the output settings. For lossless output, choose the highest quality setting available.

Your file is processed entirely within your browser using local JavaScript. It is never uploaded to any server. Only you can access your file.

For browser-based conversion, files up to 50 MB work best. Very large files may take longer depending on your device. We recommend splitting very large files before converting.

Currently, AintoB converts one file at a time to keep the browser-based process simple and private. Reload the page to convert another file.