Drop an audio or video file to measure its loudness: integrated LUFS, short-term and momentary max, loudness range, sample and true peak, and RMS. See at a glance whether it meets Spotify, YouTube, Apple Podcasts, EBU R128 or ACX targets. Runs in your browser; nothing is uploaded or changed.
WAV, MP3, M4A, FLAC, OGG, MP4, MOV or WebM. Decoded in your browser, never uploaded.
100% browser-local processing · No files uploaded to any server
How this tool decodes, analyzes, and masters your dialogue locally with zero cloud latency.
Every channel runs through the ITU-R BS.1770-4 K-weighting filters. Integrated loudness gates 400 ms blocks (absolute −70 LUFS, relative −10 LU); the momentary (400 ms) and short-term (3 s) maxima are read from the same 100 ms grid.
Loudness range follows EBU Tech 3342 (L95 minus L10 of the gated short-term values). Sample peak, a 4× oversampled true-peak estimate, unweighted RMS and a noise-floor estimate from the quietest 0.5 s are measured alongside.
The report compares your file with −14 LUFS (Spotify, YouTube), −16 LUFS (Apple Podcasts), −23 LUFS (EBU R128) and the ACX audiobook limits. Copy it as text, or open the normalizer to fix a failed target.
Explore companion utilities for dialogue cleanup, speech pacing, and mastering.
Fix a failed target with one even gain change to −14, −16 or −23 LUFS and a −1 dBFS limiter.
Raise quiet recordings by up to +18 dB with a look-ahead peak limiter.
Clean and polish dialogue before you measure the final master.
Explore the acoustic principles, ITU-R loudness standards, and pacing techniques behind this tool.
A sourced table of loudness targets for Apple Podcasts, Spotify, YouTube, EBU R128 and ACX, plus integrated vs short-term, true peak and mono vs stereo.
A sensible guide to ITU-R BS.1770 integrated loudness: understanding perceived loudness vs peak ceiling, preventing inter-sample clipping.
Clear technical breakdown: why normalization changes overall level without affecting dynamics, while compression tames peaks and brings up quiet words.
Common Questions & Technical Clarifications
Drop a WAV, MP3, M4A, FLAC or video file on the meter. It is decoded in your browser and measured with ITU-R BS.1770-4 K-weighting and gating, then shows integrated LUFS, short-term and momentary maxima, loudness range, sample peak and true peak. Nothing is uploaded.
Spotify normalizes to −14 LUFS and YouTube turns loud uploads down to roughly the same level, Apple Podcasts recommends −16 LUFS, and EBU R128 broadcast uses −23 LUFS. Keep true peak at or below −1 dBTP for all of them. ACX audiobooks use different rules: RMS between −23 and −18 dB, peaks no higher than −3 dBFS and a noise floor at or below −60 dB.
No. The LUFS meter only measures and never changes your file. If a target fails, open the Audio Normalizer, which applies one even gain change to reach −14, −16 or −23 LUFS and adds a −1 dBFS peak limiter.
True peak is estimated with 4× oversampling and a windowed-sinc interpolator, which catches inter-sample overs that a sample-peak meter misses. It is an estimate, so treat readings within a few tenths of a dB of a limit as borderline. Integrated loudness is checked in our tests against BS.1770 reference values, for example a full-scale 1 kHz sine reads −3.0 LUFS in mono.
Both are built from 3-second windows, so files shorter than 3 seconds have no value. Files quieter than −70 LUFS are gated out completely and are reported as too quiet to measure.
