Runs in your browser
Free loudness tools.
Both tools decode and measure the file in your browser, each on its own page. Nothing is uploaded, and neither asks you to sign in.
LUFS meter
Integrated loudness in LUFS, true peak in dBTP and loudness range in LU, for the whole file, with its waveform and a meter beside the numbers.
Loudness penalty calculator
The same measurement, led by how far Spotify and SoundCloud turn the file down, in LU, with each platform’s own words beside the number. The five that publish nothing are named.
Master a track.
The free preview measures your mix, masters it to the target you pick, and measures the file that comes back. Both sets of readings are labelled.