Step 1: Provide your AAC files using the button above or by toss and let go.
Step 2: Click the 'Convert' button to start the conversion.
Step 3: Fetch your converted FLAC files.
AAC to FLAC Conversion FAQ
What bitrate does the FLAC file end up at?
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A lossy FLAC is encoded at 192 kbps by default. The Audio Quality setting also offers 320 kbps for the best quality and 128 kbps for a smaller file. A lossless FLAC (WAV, FLAC) ignores the bitrate and keeps every sample.
Does converting AAC to FLAC improve the audio quality?
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No, and it is worth being blunt: nothing can. The AAC already discarded detail during its original encode, and wrapping what remains in a lossless FLAC preserves exactly that — no more. The file gets several times larger and sounds identical. It is still the right move before editing, because FLAC will not add a second generation of artefacts when you export. FLAC gives you WAV fidelity at half the size, with proper metadata tags and embedded artwork, which is why it dominates lossless music libraries. AAC is patent-encumbered, and a handful of very old players still refuse it where they would accept an MP3.
Will the FLAC play in my car or on older hardware?
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Often not. AAC is decoded by essentially everything, including car head units and elderly players; FLAC needs software that knows the codec, which standalone hardware frequently does not have. If the destination is a car stereo or a portable player, that is a strong argument for staying on AAC. FLAC is still several times larger than a good lossy file, and Apple’s ecosystem only added support recently and grudgingly.
Will going from AAC to FLAC actually reduce my audio quality?
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If AAC is lossy (MP3, AAC) and FLAC is lossless (WAV, FLAC), the FLAC is no better than the AAC — you cannot recover information already discarded by the lossy AAC codec. If AAC is lossless and FLAC is lossy, expect the FLAC encoder to recompress; at 192 kbps the loss is imperceptible to most ears.
Can I batch-convert hundreds of AAC files into FLAC?
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Several files in one job need a paid plan. Free use is one file per conversion, one conversion an hour. On a paid plan you can add several files to one job, then download each result on its own or all of them in one ZIP.
Can I normalize loudness in the AAC to FLAC step?
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Not in this step. The converter has no loudness setting and leaves the level as it is. To even out the volume, run the finished FLAC through a Normalize tool on this site.
Will the FLAC play on my car stereo / iPod / Sonos / Bluetooth speaker?
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MP3 plays almost everywhere. AAC plays on Apple devices, most Android phones and Sonos. FLAC plays on Sonos and Android but not on older iPods, and WAV plays on nearly everything but makes large files. There are no device presets on this page, so choose the target format your player supports.
Is my AAC file private during conversion?
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Yes. Uploaded AAC files are processed on our own conversion servers, no person reviews them, and they are never shared. The upload and the converted FLAC are both deleted automatically about 24 hours after the conversion, which leaves time to download the result. See /privacy/ for the full policy.
How long does converting a 1-hour AAC to FLAC take?
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It depends on the size and length of the file. Small documents and images are usually ready quickly. Long videos take the longest, because most video conversions re-encode every frame.
