1Upload the FLAC audio files you want brought to a consistent level — a whole set at once is exactly the case this is for.
2Pick a target: about -14 LUFS for streaming platforms, -16 LUFS for podcasts, -23 LUFS for broadcast.
3Run the analysis; integrated loudness and true peak are measured before any gain is decided on.
4Download the normalized FLAC file, with the dynamics inside each track left untouched.
Normalize FLAC Loudness FAQ
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.
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.
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 Normalize FLAC Loudness cost anything?
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No. Normalize FLAC Loudness is free with no account required, and nothing is added to the audio. Uploads are deleted from the workers shortly after the job finishes.
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 200 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.
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.
Why does a MP3 site host Normalize FLAC Loudness?
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MP3.to is built around the format that made portable audio ordinary: universally playable, small enough to ignore, and lossy in a way that only matters if you keep re-encoding it. Audio jobs cluster: the same person who needs a format changed usually needs the file cut, levelled or made smaller in the same sitting. Putting Normalize FLAC Loudness behind the same upload, the same caps and the same account is what turns three tabs into one.
What should I do with the result once Normalize FLAC Loudness is finished?
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The converter on this site moves audio between MP3, WAV, FLAC, M4A, OGG and Opus, so the output format is a decision you can leave until the end rather than commit to at the start. Doing that after Normalize FLAC Loudness rather than before means the encode happens once, on the file you actually settled on, instead of twice.
Is Normalize FLAC Loudness here the same tool the sibling sites run?
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The engines are shared — the same ffmpeg build, the same workers, the same limits. What a MP3 site adds is a point of view about bitrates, about what survives an encode and about when a lossless intermediate is worth the upload time. It also starts from one fact about the format this site is named after: MP3 frames are fixed-size blocks, so a cut lands on a frame boundary and gapless playback markers do not survive a re-encode.
Do I need an account, and does anything get kept?
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No account, and nothing is kept: uploads are deleted from the workers shortly after the job finishes, nothing is listened to and nothing is indexed. Free accounts exist for history and batch size, not for access.
