What is LUFS and how is it different from dB?

LUFS (Loudness Units relative to Full Scale) weights frequencies the way our ears hear them and integrates over time, so it reflects how loud something sounds; peak dBFS only looks at the highest sample. Two songs with the same peak can differ by 10 dB or more in LUFS, which is why streaming services normalize by LUFS.

My track is −9 LUFS, louder than Spotify’s −14. Is that a problem?

It isn’t penalized — the platform simply turns it down by about 5 dB so it plays as loud as everything else. But a heavily limited master can sound flatter once turned down, so many engineers now master between −14 and −10 LUFS and keep the true peak at or below −1 dBTP.

What’s the difference between true peak and sample peak?

Sample peak is the largest digital sample; when the signal is reconstructed into a continuous waveform, peaks between samples can be higher. True peak estimates them with 4× oversampling. These inter-sample peaks can distort after MP3 or AAC encoding, which is why platforms require a true peak of −1 or −2 dBTP at most.

Why is the mono podcast target −19 LUFS?

A mono program plays from both speakers of a stereo system and sounds about 3 dB louder than it measures, so −19 LUFS mono sounds as loud as −16 LUFS stereo. With “Measure mono as dual-mono” ticked, mono files are measured that way, matching Apple Podcasts and similar platforms.

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📶Loudness Meter Online - Measure LUFS, True Peak & LRA

Upload music, a podcast or a video and get a complete loudness report: integrated loudness (LUFS) per ITU-R BS.1770-4 / EBU R128, the maximum short-term (3 s) and momentary (400 ms) loudness, loudness range (LRA), true peak measured with 4× oversampling, sample peak, plus RMS level, DC offset, the share of silence and the number of clipped full-scale samples. The results are checked against common delivery targets — Spotify and YouTube −14 LUFS, Apple Music −16 LUFS, stereo podcasts −16 LUFS, mono podcasts −19 LUFS, EBU R128 broadcast −23 LUFS and US ATSC A/85 −24 LKFS — with a pass / too loud / too quiet / true-peak verdict for each, how many dB you would need to change and whether raising the level would push the true peak over the limit. A link takes you straight to Normalize Audio when a fix is needed. A short-term loudness graph shows how the level moves through the file, with the target and integrated lines overlaid. Measure several files at once, compare them in one table and export everything as CSV.

Free · No sign-up · Runs in your browserLast updated: 2026-10-26

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How to use Loudness Meter

1Upload one or more audio or video files
2Choose how mono is measured and the silence threshold, then click Measure loudness
3Review the table, platform checks and loudness graph, and download the CSV report

FAQ

What is LUFS and how is it different from dB?: LUFS (Loudness Units relative to Full Scale) weights frequencies the way our ears hear them and integrates over time, so it reflects how loud something sounds; peak dBFS only looks at the highest sample. Two songs with the same peak can differ by 10 dB or more in LUFS, which is why streaming services normalize by LUFS.
My track is −9 LUFS, louder than Spotify’s −14. Is that a problem?: It isn’t penalized — the platform simply turns it down by about 5 dB so it plays as loud as everything else. But a heavily limited master can sound flatter once turned down, so many engineers now master between −14 and −10 LUFS and keep the true peak at or below −1 dBTP.
What’s the difference between true peak and sample peak?: Sample peak is the largest digital sample; when the signal is reconstructed into a continuous waveform, peaks between samples can be higher. True peak estimates them with 4× oversampling. These inter-sample peaks can distort after MP3 or AAC encoding, which is why platforms require a true peak of −1 or −2 dBTP at most.
Why is the mono podcast target −19 LUFS?: A mono program plays from both speakers of a stereo system and sounds about 3 dB louder than it measures, so −19 LUFS mono sounds as loud as −16 LUFS stereo. With “Measure mono as dual-mono” ticked, mono files are measured that way, matching Apple Podcasts and similar platforms.