Loudness checker

Check your track’s loudness in three steps

1. Choose a WAV, MP3, FLAC or other audio file, or try the included original beat. It is decoded and measured in your browser.
2. Read the integrated loudness, true peak and loudness range, and the loudness-over-time chart.
3. Check the platform table to see whether your file will be turned down or up, copy the report, or send the file to the normalizer with the target you need.

What the numbers mean

Integrated loudness (LUFS) is the average loudness of the whole file, measured the way BS.1770 defines it: K-weighted to match how we hear, with very quiet passages gated out. This is the number streaming services compare with their target. Short-term loudness is the same measure over a sliding 3 second window, and momentary over 400 milliseconds; the chart shows both. Loudness range (LU) is the spread between the quieter and louder parts of the file, from the 10th to the 95th percentile of short-term loudness: a heavily limited pop master may read 4 LU, a film or a classical piece 15 LU or more. True peak (dBTP) is the highest level of the reconstructed waveform, including peaks that fall between samples; sample peak only looks at the stored samples.

Turned down is not a penalty

When a platform turns a loud master down, it loses nothing but level: it plays back at the same loudness as everything else. What it keeps is the squashed dynamics that made it loud, so a master pushed to −7 LUFS can sound flatter next to a −14 LUFS master with more punch. Turning up is different. Spotify raises a quiet track only until its true peak would pass −1 dB, so a quiet master with sharp peaks stays quieter than the target. The table shows both cases for your file.

Why some rows say “no official number”

Apple Music, YouTube, Amazon Music, TIDAL and Deezer all level playback in some way, but none of them publishes a target level in its own documentation. Numbers for them circulate on blogs and forums, measured by third parties at one point in time; they can change without notice, so this page does not repeat them. Where a platform documents its behavior without a number, as Apple does for Sound Check and YouTube does for Stable Volume, the table quotes that instead.

True peak and lossy encoding

Streaming services re-encode your master to AAC, Ogg Vorbis or Opus. The encoder can create peaks above the original samples, and a master whose true peak sits at 0 dB may clip after encoding. Spotify asks for masters below −1 dBTP, or below −2 dBTP when the master is louder than −14 LUFS, and SoundCloud gives the same advice. Apple Podcasts requires a true peak no higher than −1 dBFS, EBU R 128 a maximum of −1 dBTP and ATSC A/85 below −2 dBTP.

Fixing a level

This page measures; it does not change the file. To bring a file to a target, pick one under the table and press the fix button: the file goes to the normalize audio tool in this browser, with that target already chosen. The normalizer applies one gain and a soft limiter at −1 dB sample peak, so check the result here again if you need a true-peak margin. For plain gain without a target, use the volume booster. How the meter works, with the EBU test results, is on how AudioClover works.