What is the difference between Peak, RMS, and LUFS normalization?

Peak normalization scales audio so the loudest sample reaches a target level - fast but doesn't account for perceived loudness. RMS normalization targets the average power level, giving more consistent results across tracks. LUFS (Loudness Units Full Scale) is the industry standard per ITU-R BS.1770 - it applies frequency weighting and gating to measure loudness the way humans perceive it. LUFS is what streaming platforms use.

What LUFS level should I use for Spotify?

Spotify normalizes all tracks to -14 LUFS. If your track is louder, Spotify will turn it down; if it's quieter, it may be turned up (with potential quality loss). Mastering to -14 LUFS ensures your track plays at the volume you intended. Use the "Spotify (-14)" preset for one-click targeting.

What LUFS levels do other platforms use?

YouTube targets -14 LUFS, Apple Music and Apple Podcasts use -16 LUFS, and the EBU R128 broadcast standard is -23 LUFS. Each platform has a preset button in this tool so you can target the right level instantly.

What audio formats are supported?

WAV and MP3 files are supported. WAV files are normalized and output as WAV (lossless). MP3 files are decoded, normalized, and re-encoded as MP3 at 192 kbps.

Does normalizing MP3 reduce quality?

Yes, slightly. MP3 is a lossy format, so decoding and re-encoding introduces a small amount of generation loss. For the best results, normalize WAV files and then convert to MP3 using the WAV to MP3 Converter tool.

Does my audio get uploaded to a server?

No. All processing - including LUFS measurement with K-weighting filters - happens entirely in your browser using the Web Audio API. Your audio files never leave your device.

Will normalization cause clipping?

The tool includes a built-in limiter. If the gain needed would push any samples above 0 dBFS, they are clamped and you'll see a "Limiter engaged" warning. To avoid this, use a lower target level or switch to LUFS mode which typically requires less extreme gain adjustments.

Audio Normalizer

Adjust audio levels using peak, RMS, or LUFS normalization. Presets for Spotify, YouTube, Apple Music, and podcasts. Free, browser-based.

🔒 Your audio stays in your browser - nothing is sent to our servers

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Drop an audio file here or click to browse

WAV and MP3 supported

How to Use

Three steps to get started

Upload your audio file

Drag and drop a WAV or MP3 file onto the upload area. The tool instantly analyzes your audio and shows Peak, RMS, and LUFS levels.

Choose mode and target

Select Peak, RMS, or LUFS normalization. Use platform presets (Spotify, YouTube, Apple Music, Podcast) or set a custom target level with the slider.

Normalize and download

Click "Normalize" to process. Review the before/after levels and gain applied, then download the normalized file in the same format as the original.

About This Tool

Professional audio normalization in your browser

Audio normalization is the process of measuring a recording's level and applying a single, constant gain change so it lands on a chosen target. The word "constant" is the important part: normalization moves the whole file up or down by one number and leaves the internal dynamics untouched. That is what separates it from compression, which changes loud and quiet passages by different amounts and therefore alters how the performance feels.

Three normalization modes: Peak normalization finds the single loudest sample and scales everything so that sample hits your target - fast and completely safe from clipping, but a poor guide to how loud something sounds, since a sparse acoustic take and a dense mix can share an identical peak while differing by 10 dB in perceived level. RMS normalization averages power over time, which tracks perception much better. LUFS normalization, defined by ITU-R BS.1770 and refined through revision BS.1770-4, is the standard the industry actually settled on: it applies a two-stage K-weighting filter - a high-shelf modelling the head's acoustic effect plus a high-pass rolling off sub-bass - and then gates out passages more than 10 LU below the ungated mean so silence and fades do not drag the reading down.

Platform presets: One-click buttons for Spotify (-14 LUFS), Apple Music (-16 LUFS), YouTube (-14 LUFS), podcasts (-16 LUFS), broadcast (-23 LUFS / EBU R128), and loud CD masters (-9 LUFS). Or set any custom target with the slider.

Why the loudness war ended

Through the 1990s and 2000s, mastering engineers pushed integrated loudness ever higher - some releases landed near -5 LUFS - because a louder master won A/B comparisons on radio and CD changers. Streaming normalization removed the prize. Spotify, YouTube, Apple Music, Tidal, and Amazon all measure each track on upload and attenuate anything above their reference, so a -6 LUFS master and a -14 LUFS master play back at identical volume. The only surviving difference is that the loud master has been squashed to get there and now sounds flatter than the one that was left alone.

Practical guidance: master to roughly -14 LUFS integrated with true peaks at or below -1 dBTP. That headroom is not superstition - lossy encoders reconstruct a waveform that can overshoot the original samples, so a file peaking at exactly 0 dBFS will inter-sample clip once Spotify transcodes it to Ogg Vorbis or AAC. Podcast producers targeting -16 LUFS for mono spoken word should also watch loudness range, since speech with an LRA above about 8 LU becomes unlistenable in a car.

Analysis and rendering both use the Web Audio API inside this page, including the K-weighting filters, so files are never uploaded. Unreleased masters, client sessions, and confidential interview recordings stay entirely on your own machine.

FAQ

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