UtilityKit

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Audio Loudness Normalizer (LUFS)

Normalize loudness of MP3, WAV, M4A, OGG and FLAC files using ffmpeg loudnorm (EBU R128). Hit Spotify, podcast or broadcast targets — runs locally via ffmpeg.wasm.

About Audio Loudness Normalizer (LUFS)

Audio Loudness Normalizer applies EBU R128 / LUFS loudness normalization to any audio file using ffmpeg's loudnorm filter. Drop in an MP3, WAV, M4A, OGG or FLAC, pick a target loudness (Spotify -14, Apple/podcast -16, audiobook -18, EBU broadcast -23), set a true-peak ceiling, choose an output format, and download the normalized file. The whole pipeline runs locally in your browser via ffmpeg.wasm — files never leave your device. Loudness normalization is different from peak normalization: instead of rescaling to a maximum sample value, it adjusts perceived loudness across the whole file using a psychoacoustic model. That's the standard streaming services and broadcasters use to keep tracks consistently loud without clipping. Use this tool to prep podcast episodes, master a music release for streaming, or unify audiobook chapters that were recorded at different volumes.

Why use Audio Loudness Normalizer (LUFS)

  • Hits broadcast / streaming loudness targets exactly (LUFS, not just dB)
  • EBU R128 / ITU BS.1770 algorithm — the same standard major platforms use
  • True peak control prevents inter-sample clipping after codec re-encoding
  • 100% private — files are processed locally via ffmpeg.wasm
  • No watermark, no signup, no daily cap
  • Works on MP3, WAV, M4A, OGG and FLAC inputs

How to use Audio Loudness Normalizer (LUFS)

  1. Click or drag your audio file onto the upload area.
  2. Pick the target loudness — -14 LUFS for streaming, -16 LUFS for podcast, -18 LUFS for audiobook, -23 LUFS for EBU broadcast.
  3. Set the true peak ceiling (-1.5 dBTP is a safe default that survives codec re-encoding).
  4. Pick an output format — WAV for lossless, MP3 for compatibility, M4A or OGG otherwise.
  5. Click 'Normalize & Download' and wait for ffmpeg.wasm to analyse and re-encode.
  6. Audition the normalized result in the inline player, then download.

When to use Audio Loudness Normalizer (LUFS)

  • Mastering podcast episodes for Apple Podcasts (-16 LUFS)
  • Preparing music tracks for Spotify / YouTube (-14 LUFS)
  • Unifying loudness across audiobook chapters
  • Hitting EBU R128 broadcast spec for radio submission (-23 LUFS)
  • Levelling voice memos before publishing or sharing
  • Avoiding the 'this episode is way quieter than the last' complaint

Examples

Podcast episode

Input: M4A recording at average -22 LUFS

Output: M4A at exactly -16 LUFS, peak ≤ -1.5 dBTP — Apple Podcasts ready

Spotify single

Input: WAV master at -10 LUFS (loud and clipping)

Output: MP3 at -14 LUFS — Spotify won't clamp it down on playback

Audiobook chapter

Input: Eight chapter WAVs ranging -19 to -25 LUFS

Output: Eight files all at -18 LUFS — consistent volume across the book

Tips

  • Use -1.5 dBTP for true peak unless you have a reason to push hotter — many lossy codecs add inter-sample peaks that can clip if you target -0.1 dBTP.
  • If the source has a wide dynamic range (classical, film score), loudness normalization may compress it more than you'd like; consider gentler manual mastering instead.
  • EBU R128 is single-pass loudnorm in this tool. A two-pass workflow is more accurate but takes twice as long; for most podcast / streaming work the single-pass result is fine.
  • Spotify, YouTube and Apple all clamp loudness above their target on playback, so targeting their value (-14, -16) gives the most consistent result across platforms.
  • If you need broadcast spec (-23 LUFS, EBU R128), keep the true-peak ceiling at -1 dBTP — this is the published spec, not the safer -1.5.

Frequently Asked Questions

What's the difference between loudness and peak normalization?▾
Peak normalization scales audio so the loudest sample hits a target. Loudness normalization adjusts perceived volume using a psychoacoustic model (LUFS) — the standard for streaming and broadcast.
What target should I pick for podcasts?▾
-16 LUFS is the de facto Apple Podcasts standard. Many podcasters also use -14 LUFS to match Spotify.
Why -1.5 dBTP instead of -0.1?▾
Lossy codecs can introduce small inter-sample peaks during decode. A -1.5 dBTP ceiling protects against playback clipping on phones and laptops.
Is this a one-pass or two-pass loudnorm?▾
Single pass. Two-pass is slightly more accurate (especially for very dynamic material) but takes twice as long; for typical podcasts and music the difference is small.
Does it preserve dynamics?▾
Mostly. Loudnorm with default LRA=11 leaves most dynamics intact. Very dynamic material (orchestral, film score) may see more compression than you'd want — manual mastering is gentler.
What does the LRA value mean?▾
Loudness Range — how much loudness varies through the file. EBU R128 targets 11 LU; the tool uses that value.
Are my files uploaded?▾
No — ffmpeg.wasm runs in your browser. The audio never leaves your device.
Will my file get bigger or smaller?▾
Output size depends on the format and bitrate (192 kbps default for lossy formats). Loudness normalization itself doesn't change file size meaningfully.

Explore the category

Audio Format Converter Convert audio between MP3, WAV, OGG, M4A and FLAC in your browser. Choose bitrate or sample rate, then download. Runs locally via ffmpeg.wasm — no uploads. Audio Compressor Shrink MP3, WAV, M4A, OGG and FLAC files by re-encoding at a lower bitrate. Choose 32–320 kbps, pick MP3, OGG or M4A output, then download. 100% browser-side via ffmpeg.wasm. Audio Reverser Reverse any audio file so it plays backwards. Drop MP3, WAV, M4A, OGG or FLAC, choose output format, and download. ffmpeg.wasm areverse — no upload. Audio Speed & Pitch Changer Speed audio up or slow it down without changing pitch, or shift pitch in semitones independently of speed. MP3, WAV, M4A, OGG, FLAC. ffmpeg.wasm in browser. Audio Merger Concatenate multiple MP3, WAV, M4A, OGG or FLAC files into one continuous audio track. Drag to reorder, set output format and bitrate, then download. MP3 Cutter & Audio Trimmer Trim MP3, WAV, M4A and OGG audio with a visual waveform editor. Set start and end with sliders, preview the selection, then download.

Glossary

LUFS
Loudness Units relative to Full Scale — a perceptual measure of how loud audio sounds, accounting for human hearing.
EBU R128
European Broadcasting Union recommendation for loudness normalization. -23 LUFS, -1 dBTP true peak, 11 LU range.
ITU BS.1770
International Telecommunications Union loudness measurement algorithm — the technical basis for LUFS.
True peak (dBTP)
The maximum inter-sample peak after codec reconstruction. Setting a ceiling here prevents clipping on lossy playback.
Loudnorm filter
ffmpeg's implementation of EBU R128 loudness normalization. Used here in single-pass mode.
Loudness range (LRA)
The variation in loudness across a file. Set to 11 LU here to match EBU R128 expectations.