AAC to FLAC Converter
Processing entirely on your device — large files may take a moment.
AAC Audio and FLAC Lossless Audio exist for different jobs: AAC (Advanced Audio Coding) is the successor to MP3 — about 30% better quality at equal bitrates, used by YouTube, iPhone and most streamers. Convert to FLAC when you want a permanent, lossless archive of your music.
Because the whole conversion happens on your device, it is instant, unlimited and genuinely private — no accounts, no watermarks, no files on anyone's server. Multiple files are converted in one go.
How AAC compares to FLAC
| AAC | FLAC | |
|---|---|---|
| Compression | Lossy (LC/HE/xHE profiles) | Lossless (~50–60% of PCM) |
| Quality | Best-in-class at low bitrates | Bit-perfect |
| Compatibility | Streaming/broadcast standard | Players, Android, hi-res rigs |
| Best for | Streaming and mobile audio | Music collections and archival |
How to convert AAC to FLAC
- 1
Select your files
Drag & drop your AAC files onto the area above, or click to browse. You can add multiple files at once for batch conversion.
- 2
Convert instantly
Click "Convert to FLAC". The conversion runs entirely inside your browser using WebAssembly — no upload, no queue, no waiting.
- 3
Download results
Download each converted FLAC file individually, or grab everything at once as a ZIP archive.
About the AAC format
AAC (Advanced Audio Coding) is MP3's official successor, standardized in MPEG-2 and MPEG-4 and refined over two decades. It is the audio track of YouTube, iPhone voice memos, digital radio and HE-AAC streaming — arguably the most-played codec in history. Files appear either raw (.aac, ADTS stream) or inside M4A/MP4 containers.
Its claim to fame is low-bitrate performance: HE-AAC v1/v2 keep speech and music listenable at 24–64 kbps, where MP3 collapses. Raw .aac streams carry weaker tagging than the M4A container, which is why music libraries prefer M4A even when the codec is identical.
+ Strengths
- ✓The standard of streaming, mobile and broadcast
- ✓Excellent low-bitrate behavior (HE-AAC)
- ✓Better than MP3 at equal bitrate
! Limitations
- −Raw .aac files tag poorly
- −Flavor fragmentation (LC/HE/xHE) confuses tooling
About the FLAC format
FLAC (Free Lossless Audio Codec, Xiph, 2001) compresses audio to roughly 50–60% of its PCM size and restores every bit on playback — a ZIP for music that also carries proper tags, hi-res support up to 32-bit/655 kHz on paper (24-bit/192 kHz in practice) and full open-source pedigree. It is the archive format of digital music collections.
Support followed maturity: every serious player, modern Android (system-level), most cars and streaming purists' devices handle FLAC natively. Apple resisted for years but iOS 11+ plays it, with the caveat that iTunes/Apple Music syncing still prefers ALAC. The price of losslessness is size — about five times MP3 at comparable quality.
+ Strengths
- ✓Bit-perfect lossless with real compression
- ✓Hi-res capable (24-bit/192 kHz)
- ✓Open, unpatented, tag-native
! Limitations
- −~5× the size of lossy formats
- −Apple syncing prefers ALAC
- −Overkill for casual listening
Why convert AAC to FLAC?
There is a concrete reason this conversion exists: Raw .aac files tag poorly FLAC sidesteps that — Bit-perfect lossless with real compression If that is your situation, the tool above settles it in seconds, entirely on your device.
Frequently asked questions
Is this AAC to FLAC converter really free?
Yes — completely free, with no sign-up, no watermark and no daily conversion limits. The site is supported by advertising.
Are my files uploaded to a server?
No. The conversion runs entirely inside your browser using WebAssembly, so your files never leave your device — that is what makes it instant and private.
Does it work on Windows, Mac, iPhone and Android?
Yes. Anything with a modern browser works: Windows, macOS, Linux, Android and iOS. No software installation is required.
Is there a file size limit for AAC to FLAC?
The only limit is your device's memory, since nothing is uploaded. Files up to a few hundred megabytes work fine on a modern desktop browser; very large files simply take a little longer.
Will converting AAC to FLAC reduce audio quality?
If FLAC is lossless, the output contains everything the AAC file contains — no further loss is added. If FLAC is lossy, one recompression pass is unavoidable; the quality slider controls how much. Loss that already happened in the source file can never be undone by converting.
Are tags like title and artist preserved?
Tag handling varies between target formats and this conversion focuses on the audio itself. For archival copies where tags matter, keep the original file; the converted copy is for playback and sharing.