What is LUFS and why does it matter?

LUFS (Loudness Units relative to Full Scale) measures perceived loudness, not just peak level. Streaming services normalise everything to the same level: YouTube and Spotify to −14 LUFS, Apple Music to −16 LUFS. If your master sits at −8 LUFS, the service turns it down by 6 dB — so mastering loud gains you nothing and costs you dynamics.

What is true peak and why −1 dBTP?

True peak measures the inter-sample peak that appears when a digital signal is converted back to analogue. It can exceed the sample peak by a couple of decibels. MP3 and AAC encoding pushes peaks higher still, so −1 dBTP leaves headroom and keeps the result from distorting on the listener device.

What does LRA (dynamics) tell me?

LRA (Loudness Range) describes the gap between the quiet and loud parts of a track. Below 3 LU means heavily compressed material, which can be fatiguing over a longer listen. In electronic music 3–6 LU is normal; acoustic material often runs 8–15 LU.

Does my track get uploaded?

No. The file is decoded and measured by your own browser codec and never sent to a server. The meter even works offline once the page has loaded. Nothing is stored, and the measurement disappears when you close the tab.

Why can I not measure a long mix?

The browser decodes audio to 32-bit float, which takes about 23 megabytes per minute. An hour-long mix would need over a gigabyte and crash the tab. The limit is 15 minutes, which covers single tracks — and single tracks are what you measure when mastering.

LUFS Meter

Drop a track and get integrated loudness, true peak, dynamic range and a phase check. Measured to the ITU-R BS.1770-4 standard in your browser — the file never leaves your device.

Drag a track here

or pick it from your device

WAV, MP3, FLAC, M4A, OGG

🔒 The file never leaves your device — everything is measured in your browser

Drop a track in the box above and measuring starts immediately.

You can drop several tracks at once — then you also see how they differ in level.

A LUFS meter tells you your track perceived loudness, peak level and dynamics. Streaming services normalise everything to the same level, so getting the level right determines how your track sounds after release.

How the calculator works and what it’s for▾

What the meter measures

Integrated loudness (LUFS) is the average perceived loudness of the whole track per ITU-R BS.1770-4. The measurement is gated: quiet passages and silence are excluded, so a long intro will not drag the reading down.

True peak measures the inter-sample peak using four-times oversampling. It reveals distortion that only appears at digital-to-analogue conversion or in lossy encoding — a plain sample peak will not show it.

LRA (Loudness Range) describes the gap between quiet and loud sections. The meter also checks DC offset and the mid/side ratio, which reveals phase problems.

Platform targets

YouTube, Spotify and Tidal normalise to −14 LUFS, Apple Music to −16 LUFS, and Amazon Music to −14 LUFS with a −2 dBTP peak ceiling. Club masters typically sit around −8 LUFS.

If your master is louder than the target, the service turns it down. Mastering loud is not rewarded: you lose dynamics without gaining loudness. If the master is quieter than the target, most services will not turn it up at all.

Why −1 dBTP

MP3 and AAC encoding reshapes the waveform, and peaks can rise after encoding. −1 dBTP leaves the headroom that keeps the result from distorting on the listener device. Amazon Music requires −2 dBTP.

Privacy

Everything is measured in your browser using the Web Audio API. The file is never uploaded and leaves no trace anywhere. Once the page has loaded, the meter works without a network connection.

🔄 Reviewed June 2026