Preserve Your AAC Audio in a Lossless FLAC Container
Upload your AAC file and download a FLAC that stops the compression chain. Ready for audiophile players, music archives, and future re-encoding.
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Audio Format Converter
Upload any audio file, choose an output format, and download the converted result. Supports MP3, WAV, FLAC, AAC, OGG, ALAC, WMA, Opus and M4A.
Drop your audio file here
or click to browse
Stop the Compression Chain
Every time a lossy file is re-encoded to another lossy format, artifacts compound. Converting your AAC to FLAC once gives you a lossless base to re-encode to MP3, OGG, or any future format without adding new artifacts each time.
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Open Format, Every Player
FLAC is patent-free and supported natively on Android, Linux, Windows, VLC, foobar2000, Plex, Jellyfin, and most dedicated music players. No licensing fees or proprietary codec required.
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FFmpeg-Powered Server Conversion
Every conversion runs through FFmpeg on dedicated servers. The AAC stream is fully decoded to PCM, then re-encoded into a FLAC container with the original sample rate, bit depth, and channel layout preserved throughout.
See It in ActionThree steps to lossless audio
Upload your AAC file
Drop your AAC or M4A file onto the tool or click to browse. The file format is validated before conversion begins.
Convert to FLAC
Click "Convert". FFmpeg decodes the AAC stream to PCM, then re-encodes it as lossless FLAC with all metadata and channel mapping intact.
Download your FLAC file
Preview the output in the browser player, then download your .flac file ready for your music library or archive.
Deep Dive
AAC vs FLAC: What Changes When You Convert
AAC is a lossy format that permanently discards audio data to keep files small. FLAC compresses audio without discarding a single sample. Here is what that difference means in practice.
Output sample rate and bit depth match the decoded AAC stream. No upsampling is applied.
Why Use This Converter
No Further Quality Loss
FLAC stops the compression chain. Re-encode to any format later without adding new artifacts on top of the AAC source.
Open and Patent-Free
FLAC has no licensing fees or patents. It works natively on Android, Linux, VLC, foobar2000, and virtually every modern media player.
Fast Conversion
Most AAC files convert to FLAC in under 30 seconds on our dedicated servers.
FFmpeg-Powered
Industry-standard FFmpeg decodes the AAC stream with accurate sample rate, bit depth, and channel layout preservation.
Who Uses It
Who Converts AAC to FLAC
Audiophiles, archivists, music producers, and app developers all have workflows where lossless FLAC is the right container.
Converts using FFmpeg on dedicated servers.
Frequently Asked Questions
Does converting AAC to FLAC improve audio quality?
No. AAC is a lossy format and any audio data discarded during the original encoding is gone permanently. Converting to FLAC decodes the existing audio into a lossless container, which prevents any further quality loss when the file is edited or re-encoded in the future.
Why is the FLAC file so much larger than the source AAC?
FLAC stores every decoded audio sample without discarding any data. Even with lossless compression applied, the result is significantly larger than a lossy AAC file. A 5 MB AAC track may expand to 30 to 50 MB as FLAC. This is expected behavior, not an error.
What sample rate and bit depth will the output FLAC use?
The output sample rate and bit depth match what the AAC decoder produces from your source file. No upsampling or bit-depth padding is applied. A typical AAC decoded from iTunes or a streaming source produces 44.1 kHz or 48 kHz 16-bit audio.
Which players and apps support FLAC?
FLAC is supported natively on Android, and by VLC, foobar2000, Winamp, Plex, Jellyfin, Kodi, Audacity, most DAWs, and virtually every dedicated hi-fi music player. On macOS and iOS, use a third-party player such as Vox or Doppler, or convert to ALAC for Apple-native playback.
Can I convert M4A files containing AAC audio?
Yes. M4A is an MPEG-4 container that typically holds AAC audio. Upload your .m4a file the same way you would an .aac file and the converter will decode the AAC stream and output a FLAC.
Is there a file size limit?
The upload limit is 100 MB per file. Most AAC tracks and albums are well within this limit.
Ready to Convert Your AAC to FLAC?
Upload your file above and get lossless FLAC audio in seconds.