Filenary

AAC to FLAC Converter

Convert AAC audio files to FLAC audio right in your browser — free, private and with no size limit.

Drop your file here

or click to browse

Choose File

On first use, a ~30 MB conversion engine is downloaded to your browser (one time only).

This file is processed in your browser and never uploaded to a server.

How to convert AAC to FLAC

  1. 1Drop your AAC file into the box above, or click to choose it from your device.
  2. 2Click Convert. The conversion runs locally in your browser — nothing is uploaded.
  3. 3Download your new FLAC file as soon as it's ready.

Why convert AAC to FLAC?

Raw AAC files aren't recognized by some older players and editors. FLAC keeps perfect CD-quality sound at around half the size of WAV.

The size math: AAC vs FLAC

At typical quality a minute of content weighs about 1.9 MB as AAC and 5.5 MB as FLAC — after conversion your FLAC file comes out about 2.9× larger.

What is AAC?

AAC is an efficient lossy audio format used by YouTube, Apple Music and most streaming services.

  • MIME type: audio/aac
  • Standardized: 1997 (MPEG-2, refined in MPEG-4)
  • Beats MP3 at the same bitrate thanks to newer psychoacoustics
  • The default audio codec of YouTube, iPhone and iTunes

What is FLAC?

FLAC is a lossless audio format that compresses audio to about half the size of WAV without losing any quality.

  • MIME type: audio/flac
  • Released: 2001 by Xiph.Org Foundation
  • Lossless: shrinks WAV by 40–60% without losing a sample
  • The audiophile archiving standard

Frequently asked questions

Is this AAC to FLAC converter free?
Yes, it's completely free with no sign-up, no watermark and no daily limits.
Are my AAC files uploaded to a server?
No. The conversion happens entirely inside your browser, so your files never leave your device.
Is there a file size limit?
Filenary sets no limit — even files over 1 GB work. The only practical limit is your device's memory.
Will converting AAC to FLAC reduce the quality?
FLAC is a lossless format, so no extra detail is thrown away during the conversion — the result looks exactly like the source.
Can I convert several AAC files at once?
This converter handles one file at a time. When it's done, click Start over to convert the next AAC file.
Does it work on iPhone, Android, Mac and Windows?
Yes. It runs in any modern browser — Chrome, Safari, Edge or Firefox — on phones, tablets and computers, with nothing to install.

More AAC conversions

Convert other files to FLAC

All file conversions

Add this tool to your website

Copy the code below and paste it into any page. It's free, needs no sign-up, and files are processed in your visitors' own browsers.