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MP3 to AAC Converter

Convert MP3 to AAC online for free: nothing to install, no watermark, files encrypted in transit and deleted automatically after conversion.

Advanced options

Drag & drop your MP3 file here, or

How to convert MP3 to AAC in 3 steps

  1. 1

    Upload your MP3 file

    Drag and drop or select the MP3 file you want to convert.

  2. 2

    Choose AAC as output

    The output format is pre-selected for you — just confirm and start the conversion.

  3. 3

    Download your file

    Once processing finishes, download your converted AAC file instantly.

MP3 vs AAC: what is the difference?

MP3 to AAC: diagram of the MP3 file being converted to the AAC format
MP3 and AAC compared
MP3AAC
Full nameMPEG-1 Audio Layer IIIAdvanced Audio Coding
TypeCompressed audioCompressed audio
CompressionLossyLossy
Developed byFraunhofer IIS / MPEGMPEG (ISO/IEC)
File extension.mp3.aac

What is MP3?

MP3 is the classic compressed audio format. It removes sounds the ear barely notices to shrink files to roughly a tenth of CD size, and it plays on every phone, car stereo and music app, which is why it remains the default for music and podcasts.

What is AAC?

AAC is the successor to MP3 and generally sounds better at the same bitrate. It is the audio format behind Apple Music, YouTube and most MP4 videos, and it is supported by all modern phones and browsers.

Tips for converting MP3 to AAC

  • Converting a compressed file such as MP3 to a lossless format does not restore detail already removed; it only makes the file larger.
  • For music, a lossless source (WAV or FLAC) gives the best result when you convert to AAC.
  • Check that your player, car stereo or editing app supports AAC before converting a whole library.
  • Keep the original MP3 file as a backup until you are happy with the converted audio.

Frequently asked questions

How do I convert MP3 to AAC online?
Upload your MP3 file above, select AAC as the output format, and click Convert. ConvertFastHub processes the file in the cloud and gives you a download link — no software installation required.
Is it free to convert MP3 to AAC?
Yes. Free accounts get 10 conversions every 24 hours with files up to 50MB. For unlimited conversions, larger files up to 1.5GB, and priority processing, upgrade to ConvertFastHub Pro.
Is my file safe when I convert it?
Files travel over an encrypted connection, are scanned automatically for malware (files up to 200 MB), are processed in an isolated worker and are deleted automatically: after 1 hour without an account, 24 hours with a free account, or 7 days with Pro.
Can I convert MP3 to AAC on my phone?
Yes. The converter runs in the browser and the work happens on our servers, so it works the same on Android, iPhone, tablets and computers — there is no app to install.
Do I need an account?
No. You can convert without signing up; results are then kept for 1 hour. A free account keeps them for 24 hours and shows your conversion history.