How to use the LUFS meter
- Drop a WAV, MP3, FLAC or M4A file into the box above, or click it to choose one.
- Wait a second or two while the browser measures it. Nothing is uploaded.
- Read integrated loudness (the whole track, in LUFS) and true peak (in dBTP). The table shows how Spotify, YouTube, Apple Music, Tidal, Amazon Music and Deezer will adjust the track.
What the numbers mean
| Reading | What it measures |
|---|---|
| Integrated loudness | Average perceived loudness of the whole file, with quiet passages gated out. This is the number streaming services normalize to. |
| Short-term max | The loudest 3-second stretch. Shows how hot the chorus or drop is. |
| Momentary max | The loudest 400 ms. Useful for spotting single hits that jump out. |
| Loudness range (LRA) | How much the loudness moves across the track, in LU. Heavily limited pop often sits around 3–6 LU, film and classical much higher. |
| True peak | The highest level of the waveform including peaks between samples, found by 4× oversampling. Keep it at −1 dBTP or lower for streaming. |
| Sample peak | The highest sample value. It can read lower than true peak, which is why it is not enough on its own. |
How many LUFS should my master be?
There is no single correct number. Most services play music at about −14 LUFS (Apple Music at −16), so a louder master is simply turned down. That does not make −14 a rule: many commercial pop, rap and electronic masters measure −10 to −7 LUFS because the producer wanted that density. What matters is that the master sounds right to you at the level it will be played, and that true peak stays under −1 dBTP.
Targets for each service, and what happens to quiet and loud tracks, are in LUFS for Spotify, YouTube and other streaming services.
LUFS vs dB
One LU equals one decibel, so a track at −10 LUFS is 4 dB louder than one at −14 LUFS. The difference is what is measured: dBFS readings on a peak meter show the level of individual samples, while LUFS is a loudness average weighted to match human hearing. Two tracks that both peak at −1 dBFS can be 10 LU apart in loudness. More in What are LUFS.
Why tracks from Suno often read quiet
A Suno track we measured came out at −16.1 LUFS integrated with a true peak of −3.7 dBTP: about 2 dB under the Spotify and YouTube level and well under typical commercial releases. YouTube will not turn it up, so next to other songs it sounds weaker. Mastering raises the loudness while keeping peaks in check; the mastered versions of that track measured −9.4 LUFS with true peak at −1.1 dBTP.