FLAC to AAC Converter

Converting FLAC to AAC produces small, high-quality files in the codec streaming services, Apple devices, and video containers all prefer. A typical FLAC compresses to about one-fifth its size as 256 kbps AAC with quality transparent to nearly all listeners.

audio_file

Drag & drop audio files here, or browse

Drop your FLAC files here

What changes when you convert FLAC to AAC

AAC is lossy, but starting from lossless source means the encoder produces its best possible output. At 256 kbps AAC most listeners cannot distinguish the result from the FLAC; at 192 kbps it's still excellent; below that you start hearing the compression on careful listening.

When to use this conversion

  • Shrinking a FLAC library for an iPhone, iPad, or Apple Watch where storage matters
  • Preparing audio for YouTube or streaming services that re-encode to AAC anyway
  • Building audio tracks for MP4 video where AAC is the standard companion codec
  • Syncing music to a car stereo that handles AAC better than FLAC

Where the output plays

AAC plays everywhere current: iOS, macOS, Windows, Android, all browsers, game consoles, smart speakers. Hardware older than about 2008 may lack AAC decoding.

About these formats

FLAC (Free Lossless Audio Codec)

FLAC is a lossless compressor: it shrinks PCM audio to roughly 50–60% of its original size and decodes back to a bit-perfect copy. It supports tags, cue sheets, and up to 32-bit / 655 kHz, which makes it the de facto format for CD rips and audiophile music libraries.

AAC (Advanced Audio Coding)

AAC is the successor the MPEG group designed to replace MP3. At 128 kbps it typically sounds as good as MP3 at 192 kbps. It's the default codec for YouTube audio, iTunes purchases, Apple Music, and nearly every streaming service that isn't using Opus or Vorbis.

How It Works

  1. Add your FLAC files Drag FLAC files onto the page, or click to pick them from your file browser. Batch uploads are fine.
  2. Choose AAC settings Pick bitrate or quality level for the AAC output. Defaults match common target use cases.
  3. Convert in your browser FFmpeg runs locally via WebAssembly. Nothing uploads. Progress shows per file so you know exactly what's happening.
  4. Download AAC files Grab each converted file individually, or download the whole batch as a single ZIP.

Features

Supported Formats

FAQ

What AAC bitrate is transparent compared to FLAC?

256 kbps AAC is transparent for nearly every listener on nearly every track. 320 kbps is overkill but harmless. Below 192 kbps you may hear subtle differences on careful A/B testing.

Is AAC better than MP3 when starting from FLAC?

Yes. AAC at 192 kbps generally equals or beats MP3 at 256 kbps, and starting from lossless FLAC gives the encoder the cleanest possible input.

What is FLAC (Free Lossless Audio Codec)?

FLAC is a lossless compressor: it shrinks PCM audio to roughly 50–60% of its original size and decodes back to a bit-perfect copy. It supports tags, cue sheets, and up to 32-bit / 655 kHz, which makes it the de facto format for CD rips and audiophile music libraries.

What is AAC (Advanced Audio Coding)?

AAC is the successor the MPEG group designed to replace MP3. At 128 kbps it typically sounds as good as MP3 at 192 kbps. It's the default codec for YouTube audio, iTunes purchases, Apple Music, and nearly every streaming service that isn't using Opus or Vorbis.

Are my files private?

Yes. The converter runs entirely in your browser using FFmpeg compiled to WebAssembly. Your audio files are never uploaded, never sent to a server, and never leave your device.

Is there a file size limit?

There's no hard limit, but because everything runs in your browser you're bounded by available memory. Files over about 2 GB total can get slow or hit browser memory limits. Process in smaller batches if you run into issues.