AAC to FLAC Converter

Convert AAC files to FLAC online, for free, with nothing to install.

To convert AAC to FLAC, select or drop your .aac file above, check that FLAC is chosen as the output, and click Convert. This conversion runs on our server, and your files are deleted 72 hours later.

What is an AAC file?

AAC – AAC audio. AAC is the successor of MP3: it sounds better at the same size. A bare .aac file is a stream of AAC frames; the usual home of AAC is the M4A file. Converting makes a new file: the sound is decoded and written again, so converting from a lossy format never brings back what was lost.

AAC Converter →

What is a FLAC file?

FLAC – FLAC lossless audio. FLAC compresses audio to about half its size without losing anything: decoding gives back exactly what went in. Converting makes a new file: the sound is decoded and written again, so converting from a lossy format never brings back what was lost.

FLAC Converter →

How to convert AAC to FLAC

  1. Click Select File, or drop your .aac files anywhere on this page. You can add several at once.
  2. Check that FLAC is chosen as the output format. On this page it is picked for you.
  3. Click Convert. When a file has to go to our server, the button says Upload and convert instead.
  4. Click Download next to each file when it's done.

AAC vs FLAC: how they compare

AACFLAC
LayoutA stream of soundA stream of sound
EditableIn audio editorsIn audio editors
Created byMPEG, 1997Xiph.Org, 2001
Best forMusic on phones and streamingKeeping music at full quality

Good to know

  • The sound is decoded and written as a FLAC file, every sample kept.
  • AAC lost detail when it was made, and FLAC cannot bring it back: the file gets bigger but sounds the same as the AAC.
  • Tags such as title and artist are kept where the new format has room for them. Only the first audio track is converted; pictures and video are left out.

Frequently asked questions

Is converting AAC to FLAC free?

Yes. Everyone gets 25 free credits a day, with no account needed. Conversions on our server use one credit per started minute of work, so most cost a single credit. Credits reset at midnight UTC.

Are my AAC files uploaded anywhere?

This conversion runs on our server, because converting audio needs ffmpeg, which does not run in a browser. Your file is sent over an encrypted connection, and both it and the result are deleted 72 hours after the conversion. The server has no internet access while it works on your file.

How large can the AAC file be?

Up to 1 GB per file. This conversion runs on our server, which accepts files up to that size.

Will the FLAC look the same as the AAC?

Yes for the sound: every sample is kept, and tags such as title and artist are kept where FLAC has room for them. The AAC lost detail when it was made, and FLAC cannot bring it back.

Can I convert several AAC files at once?

Yes. Add as many files as you like; they are converted one after another, and each one gets its own Download button.

How long does converting AAC to FLAC take?

In our tests a one-hour WAV recording became an M4A file in about 46 seconds. A song of a few minutes takes a few seconds, and most conversions cost a single credit.

Convert AAC to other formats

Convert other files to FLAC

All audio formats

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