1Upload the FLAC audio files you want brought to a consistent loudness.
2There is nothing to set: the loudness is brought to -16 LUFS (EBU R128), with true peaks kept below -1.5 dBTP.
3Run the analysis; integrated loudness and true peak are measured before any gain is decided on.
4Download the normalized FLAC file.
Normalize FLAC Loudness FAQ
How does Normalize FLAC Loudness decide the right level?
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Concretely, R128 loudness analysis drives an exact gain applied to the PCM, so a whole album can be brought to one target level with the relative dynamics inside each track untouched. The file is measured first and the correction follows from the measurement, rather than a fixed gain being applied and hoped for.
What is the difference between this and just turning it up?
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A volume change applies a number you chose. Normalisation measures how loud the file actually is and computes the gain needed to hit a target, so ten files recorded at ten different levels all arrive at the same one.
Does the source format affect normalisation?
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It does. FLAC is lossless compression — bit-identical to the source on decode, at about half the size of WAV. That determines whether the corrected audio can be written back exactly or has to be re-encoded.
Anything specific to FLAC here?
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Yes — FLAC decodes bit-identically to the source, so any number of edit-and-resave cycles cost you nothing in fidelity. Worth knowing when the goal is a consistent set rather than one file.
What loudness target should I aim for?
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About -14 LUFS is what the major streaming platforms normalise to, -16 LUFS is the usual podcast target, and -23 LUFS is the broadcast standard. Going louder than the platform target gains you nothing — the platform simply turns it back down.
Does normalisation compress the dynamics?
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No. It is a single gain adjustment for the whole file, so the relationship between the quiet and loud parts is untouched. Compression and limiting are separate operations and are not applied here.
What can I upload to Normalize FLAC Loudness?
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WAV, FLAC and AIFF, at any bit depth and sample rate up to and including 24-bit/192 kHz. Lossy files work in the same batch if you are mixing sources.
Is there a file size limit on Normalize FLAC Loudness?
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Yes: free accounts process audio up to 15 MB per file — for uncompressed PCM that is roughly twenty minutes of CD-quality stereo, so it is a real limit here in a way it is not for MP3. If you are over it, converting WAV to FLAC first is the free fix — it is lossless and roughly halves the size.
Will Normalize FLAC Loudness lower the quality of my FLAC audio files?
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No. Lossless audio is edited sample-exactly, so what comes back decodes bit-identically to what you would get doing the same edit in a desktop editor. You can repeat the cycle as many times as you like without accumulating any loss at all.
Can I run Normalize FLAC Loudness on several FLAC audio files at once?
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Yes, though lossless files are large, so the batch is bound by upload bandwidth rather than by processing. Settings apply uniformly across the set.
Are bit depth and sample rate preserved?
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Yes, unless you change them deliberately. A 24-bit/96 kHz source stays 24-bit/96 kHz — nothing is silently downsampled to 16/44.1, which is the failure mode that makes a master unusable.
Does Normalize FLAC Loudness cost anything?
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No. Normalize FLAC Loudness is free without an account, and nothing is added to the audio. The upload and the result are deleted automatically about 24 hours after the job, which leaves time to download the result.
