Free online loudness meter: LUFS, True Peak and LRA

Spotify plays music at −14 LUFS integrated. Louder masters are turned down to that level, so there is no need to go much louder than about −14 unless you want the denser sound. Keep true peak at −1 dBTP or below, and at −2 dBTP if your master is louder than −14 LUFS.

The gap between your integrated LUFS and the platform's level. A master at −9 LUFS plays 5 dB lower on Spotify's default setting (−14 LUFS), and 7 dB lower on Apple Music (−16). This is often called the loudness penalty. Hear it on streaming plays your file at each service's level, so you can hear the change before you release.

dBFS measures signal level: how close the samples are to full scale. LUFS measures perceived loudness, with K-weighting and gating from ITU-R BS.1770, so it tracks how loud a song sounds. A change of 1 LU equals 1 dB.

−1 dBTP is the usual ceiling for streaming delivery, and −2 dBTP gives lossy encoding more room on loud masters. EBU R128 broadcast allows up to −1 dBTP and ATSC A/85 in the US up to −2 dBTP.

Platforms normalize every track to the same loudness. A heavily limited master is turned down just like a dynamic one, but it has smaller peaks and transients left, so it can sound flatter and quieter. Check PSR and PLR: very low values mean a lot of compression.

Loudmeter's LUFS analyzer follows ITU-R BS.1770-5 and EBU R128 for integrated, short-term and momentary loudness, gating and loudness range, and measures true peak with 4× oversampling. Different meters can differ by a few hundredths of a dB on true peak, which is normal.

Meters that follow ITU-R BS.1770 read the same integrated LUFS for the same file, to rounding. A gap usually means a different setup: a selection instead of the whole file, gating switched off, a momentary reading compared with an integrated one, or one channel measured instead of two, which reads about 3 LU quieter.

No. The online analyzer measures finished files, so measure the exact file you will upload. For a moving number while you mix, LOUDMETER: Menu Bar ($9.99) meters whatever your Mac is playing, and the free iPhone and iPad app can mirror it.

Each red mark is a moment where the true peak goes over 0 dBTP (it reads +0.1 or more). The time is listed under the waveform, so you can find the spot in your session and fix it. Click a mark to hear that moment.

Yes. After the analysis, press play under Hear it on streaming and pick a service: the file plays at the level Spotify (−14 LUFS), Apple Music (−16), YouTube, Amazon Music, TIDAL, Deezer or SoundCloud would play it. Switch while it plays to compare with the original. You can pick each service's quality too: lossless plays your original samples, and lossy ones, such as Spotify's 160 kbps Ogg Vorbis or Apple Music's 256 kbps AAC, are encoded in your browser with that codec and bitrate. Nothing is uploaded.