On this device
How loud is your master, really?
Drop the WAV or FLAC. Integrated loudness, loudness range and true peak, measured to ITU-R BS.1770 in this browser. Then what Spotify does with each number, from Spotify's own page. The file is never uploaded.
Integrated
Loudness range
True peak
Numbers are the start. Take this track into Thermal and the Mix Read turns them into three moves for this mix. How to check the file never left.
The method
What these numbers actually are.
Integrated loudness follows ITU-R BS.1770-4: K-weighting, 400 ms blocks every 100 ms, an absolute gate at -70 LUFS and a relative gate 10 LU under the mean. Loudness range follows EBU Tech 3342: 3 second blocks, gated 20 LU under the mean, read from the 10th to the 95th percentile. True peak oversamples four times between samples. On the EBU's reference signals this meter reads within 0.1 LU. Format, sample rate and bit depth come from the file's own header, not the decoded copy.
Questions
Should I master to -14 LUFS?
Not because of Spotify. Spotify turns louder masters down to -14. It raises softer ones only as far as their peaks allow, keeping 1 dB of headroom. Loud is a sound you can choose. What changes is the true peak it asks for: under -1 dBTP, or under -2 dBTP when louder than -14.
What about Apple Music and YouTube?
They set their own levels and do not publish one number for artists. This page will not guess one for them.
Why can my DAW read a little differently?
Meters differ in how they oversample true peak and where a file starts and ends. Integrated loudness should agree within a few tenths. If it does not, check that both meters see the same file.