Convert AAC to FLAC online
Free, no sign-up, no limits. Drop your AAC files, get FLAC files back in seconds.
1 files converted so far
Drop your AAC files here
or · multiple files accepted
Local conversion: your files never leave your device.
Why convert AAC to FLAC?
Heads up: going from AAC (compressed) to FLAC (lossless) does not restore the quality that was lost. It is useful for importing the file into editing or transcription software or a sampler that requires FLAC, not for "improving" the sound.
How to do it, step by step
- Drop your AAC fileinto the area at the top of the page (or several files at once). On mobile, tap the area and pick the file from your apps.
- Check the output format: FLAC is already selected. FLAC is a lossless format: there is no quality setting, the sound is reproduced identically. The file will be noticeably larger than a compressed format.
- Start the conversion.The FFmpeg engine loads once (≈ 10 MB), then each file is processed in a few seconds without leaving your device.
- Download your FLAC, directly or as a .zip if you converted several files. The name and metadata (title, artist, cover art) are preserved.
The AAC format (Advanced Audio Coding)
AAC is the successor to MP3: at the same bitrate, the sound is better. It is the audio codec of YouTube, Apple Music, digital TV and most MP4 videos. A raw .aac file (without the M4A container) is rarer and less well supported than its .m4a equivalent.
- Better quality than MP3 at the same bitrate
- Standard for video and streaming
- Raw .aac file poorly compatible
- No metadata without a container
The FLAC format (Free Lossless Audio Codec)
FLAC compresses audio with zero loss: the file is 40 to 60% the size of the original WAV but reproduces exactly the same sound. It is the format of choice for audiophiles and music archives. It is free, open, and supports metadata and cover art.
- Quality identical to the original
- Free and open format
- Supports tags and cover art
- Files 5 to 10 times larger than an MP3
- Not played by Apple devices without a third-party app
AAC vs FLAC comparison
| AAC | FLAC | |
|---|---|---|
| Compression | Lossy | Lossless |
| Typical size (1 min, music) | ≈ 1.2 MB (160k) | ≈ 5 MB |
| Common use | streams extracted from videos, digital recorders, streaming | CD archiving, audiophiles, Bandcamp, Qobuz |
| Metadata (title, cover art) | Limited | Yes |
Frequently asked questions
Does converting AAC to FLAC lose quality?
No: FLAC is a lossless format. The sound of the converted file is strictly identical to that of the original AAC, but the quality already lost during AAC compression is not recovered.
Is the AAC to FLAC converter free?
Yes, with no limit on the number of files, no sign-up and no watermark. Each file can be up to 200 MB.
Are my AAC files uploaded to the internet?
No. The AAC to FLAC conversion is performed by FFmpeg directly in your browser (WebAssembly). Your files never leave your computer or phone.
How do I convert AAC to FLAC on iPhone or Android?
Open this page in Safari or Chrome, tap the drop area, select your AAC file (from Files, Voice Memos, Downloads or WhatsApp), then tap "Convert". The FLAC downloads to your files.
Can I convert several AAC files at once?
Yes, add all your files in one go. They are converted one after another and a button lets you download everything as a .zip archive.