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ITU-R BS.1770 / EBU R128 · Peak Limiter

Normalize Audio Online Free (LUFS Meter)

Normalize dialogue, podcasts, and video audio to -14, -16, or -23 LUFS. Loudness is measured with ITU-R BS.1770 K-weighting and gating, and a -1 dBFS peak limiter catches overs. Everything runs in your browser.

Loudness Normalizer

Runs locally in your browserReady

Drop an audio or video file here

WAV, MP3, M4A, FLAC, OGG, MP4, MOV or WebM. Decoded in your browser, never uploaded.

Choose file

100% browser-local processing · No files uploaded to any server

Acoustic Engineering Guide · Architecture

How this tool works in browser memory

How this tool decodes, analyzes, and masters your dialogue locally with zero cloud latency.

01Phase 01

ITU-R BS.1770 K-Weighting Scan

Applies the BS.1770 K-weighting filters (high-shelf pre-filter and RLB high-pass) to every channel, then gates 400 ms blocks (absolute -70 LUFS, relative -10 LU) to measure integrated loudness.

02Phase 02

Target Gain Calibration

Computes the exact decibel offset required to align speech with -16 LUFS (Apple Podcasts/Spotify), -14 LUFS (YouTube/Web), or -23 LUFS (EBU R128 broadcast).

03Phase 03

True-Peak Ceiling Protection

A look-ahead peak limiter keeps every sample at or below -1.0 dBFS. True peak is estimated with 4x oversampling and shown for input and output, so you can check headroom before export.

Frequently Asked Questions

Common Questions & Technical Clarifications

What is the difference between peak normalization and LUFS normalization?+

Peak normalization simply amplifies the loudest instantaneous sample to 0 dBFS, often leaving speech quiet or uneven. LUFS (Loudness Units Full Scale) measures perceived human loudness across the entire recording, ensuring uniform volume between different speakers and episodes.

What LUFS target should I use for podcasts vs YouTube video?+

For podcasts (Apple Podcasts, Spotify), the recommended target is -16 LUFS for stereo and -19 LUFS for mono. For YouTube and web video, the platform standard is -14 LUFS. Both targets require a -1.0 dBFS True-Peak ceiling.

Why is a True-Peak limiter at -1.0 dBFS essential for online audio?+

When streaming platforms transcode uncompressed WAV audio into lossy AAC or MP3 formats, inter-sample peaks can rise by 0.5 to 0.8 dB. Leaving about 1 dB of headroom helps prevent that distortion. This tool limits sample peaks to -1.0 dBFS and shows an estimated true peak so you can confirm the headroom.

Will normalizing audio online crush my voice dynamics?+

No. AutoSilenceCut applies one even gain change across the file and uses the look-ahead limiter only on peaks that would exceed -1.0 dBFS. Large gain increases on very dynamic audio make the limiter work harder, which can leave the result slightly under the target; the output meter shows the measured result.

Is my audio uploaded to a server for normalization?+

No. All K-weighting filters, RMS energy sums, and limiter passes execute 100% inside your local browser via Web Audio with complete data privacy.