LUFS Meter
Drop a file and read its integrated loudness, true peak, momentary and short-term maxima and loudness range, with a chart you can scrub. Free, in the browser, nothing uploaded.
The LUFS Meter tells you how loud a track is the way streaming platforms and broadcasters measure it, not how high the waveform goes. Loudness units are the language every platform speaks, so this is the number to know before you upload anywhere.
#Using it
- Select Audio FileMP3, WAV, FLAC, AAC, M4A, OGG and friends. One file at a time, any length. The file is opened right there in your browser.
- Wait a momentA full song takes a few seconds. The readings appear together with the chart.
- Read, then listenPress play to hear the track while the playhead moves across the chart. Click anywhere on the chart to jump there; the loudest moments are easy to find that way.
- New AudioThe button at the top right loads the next file. Nothing to clean up.
#What you get
| Reading | Meaning |
|---|---|
| Integrated LUFS (the big number) | The loudness of the whole track, start to finish. This is what platforms use to decide how much to turn you down or up. |
| True Peak | The highest peak the file reaches, in dB. Closer to 0 means less headroom; most delivery specs ask for -1 or lower. |
| Max Momentary | The loudest 400 millisecond moment. Think of it as the biggest hit in the song. |
| Max Short-term | The loudest 3 second stretch. Closer to how a chorus feels than a single hit. |
| Loudness Range | How far the quiet and loud sections sit apart, in LU. Small values mean consistent; large values mean dynamic. |
The chart plots short-term loudness (3 second window) and momentary loudness (400 millisecond window) over time, with the integrated value as a dashed line across it. Where the curves sit above the line the song is louder than its own average; where they dip below, it is quieter.
#The verdict line
Under the number there is a one-line verdict. It is a rule of thumb for releases headed to streaming, not a law.
| Integrated loudness | Verdict |
|---|---|
| Quieter than -16 LUFS | Too quiet |
| -16 to -14 LUFS | Almost perfect but could be better |
| -14 to -6 LUFS | Perfect loudness for many tracks |
| -6 to -4 LUFS | A bit too loud |
| Louder than -4 LUFS | Way too loud |
#Good to know
- Everything happens in your browser. The file is not uploaded, not stored, not seen by anyone.
- The meter follows the ITU loudness standard that platforms and broadcasters use, so its numbers match the professional meters.
- Measure the file you will actually deliver. A 320 kbps MP3 and its WAV source read within a hair of each other, but a rough bounce with the limiter off will not.
- The chart can be saved as an image from its toolbar if you want to show someone where the song peaks.
Why is the number negative?
Loudness is measured down from digital full scale, so 0 is the ceiling and everything real sits below it. -6 LUFS is very loud, -23 LUFS is quiet.
LUFS or dB, what is the difference?
dB measures signal level; LUFS measures how loud it sounds to ears, giving more weight to the frequencies we are sensitive to. Two tracks with the same peak level can differ by many LUFS.
Which number matters most for streaming?
Integrated LUFS decides the normalisation, True Peak decides whether the file survives lossy encoding without clipping. Watch both.
Can I measure part of a song?
Not yet. The meter reads whole files. Export the section you care about and drop that.