Queue AAC audio
Choose one or more non-empty .aac files up to 100 MB each. A source audio control appears when the browser can decode that AAC file.
Free online AAC to FLAC converter
Create lossless FLAC audio from AAC files.
Queue AAC files, make a new FLAC from the first audio stream, then listen to and download every completed result.
- Files not stored
- Queue AAC files
- 100 MB each
Processed by our self-hosted conversion engine
Supported files
AAC in. FLAC out.
AACFLAC
Add AAC audio files up to 100 MB each. Fileverses creates a new FLAC result with this route’s documented conversion profile; review the completed download before using it elsewhere.
How it works
One queue. A new FLAC file.
Create lossless FLAC audio
Start the queue to have FFmpeg map the first audio stream from each AAC file and encode it as a new lossless FLAC file.
Listen and download
Inspect every completed FLAC in the queue when the browser supports it, then download that separately named audio result.
Limits and quality
A new FLAC file, with source-specific trade-offs.
Each result is a newly encoded lossless FLAC, not copied AAC audio. Lossless FLAC encoding cannot restore audio detail lost in an earlier AAC encode, and no output size is promised.
Convert AAC nowAAC sources with audio
This route accepts non-empty .aac files up to 100 MB each. The selected file must be readable by the host FFmpeg installation and have an audio stream.
New FLAC does not restore detail
Each result is a newly encoded lossless FLAC, not copied AAC audio. Lossless FLAC encoding cannot restore audio detail lost in an earlier AAC encode, and no output size is promised.
First audio stream only
The profile maps only the first audio stream, removes source metadata and chapters, and excludes video. It does not preserve alternate audio tracks, subtitles, attachments, original codecs, or metadata, and has no trimming, sample-rate, channel, bitrate, or compression controls.
AAC to FLAC FAQ
Questions, answered.
What AAC files can I convert to FLAC?+−
This converter accepts non-empty .aac files up to 100 MB each. FFmpeg must be able to read the AAC file and find an audio stream for conversion to succeed.
What does the downloaded FLAC contain?+−
A successful result is a newly encoded FLAC file. It contains only the first audio stream from the AAC source.
Can I convert several AAC files at once?+−
Yes. Add multiple supported AAC files to the queue. The browser submits one real server-side conversion at a time, and every successful row receives its own FLAC control and download button.
Will FLAC recover original quality or always be smaller?+−
No. FLAC encoding is lossless from the decoded AAC audio, but it cannot recover detail lost in an earlier AAC encode. The final size depends on the source and encoder output and is not promised to be smaller.
Does this keep alternate audio tracks or metadata?+−
No. The profile maps only the first audio stream, removes source metadata and chapters, and excludes video. It does not promise alternate-track, subtitle, attachment, original-codec, or metadata preservation.
Can I choose FLAC settings or trim the audio?+−
No. This route has no trimming, stream-selection, sample-rate, channel, bitrate, or compression controls. It uses its fixed FLAC profile.
Are files kept after conversion?+−
Each source and output exists in a temporary server directory only while its conversion runs. The directory is removed whether the job succeeds or fails.