Good site, but it has some frustrating limitations that make it vastly less useful, specifically regarding the phenomenon in the article. The search UI doesn’t expose the release code (and many entries don’t even include it), so when it says “vinyl” you have no idea which of the possibly dozens of releases it refers to, some of which can be awful, like the article points out.

I’m willing to help fix this, but the source code is not public, and when I emailed the author I got no response.

PSA 2: the formula used here can easily be gamed via inaudible phase alteration and can't be used to compare CD and LP. Ears are still much better until a correctly designed metric arrives.

There are usefull software components (=extensions) for the foobar2000 music player (sadly Windows only player) that can analyze the dynamic range and loudness according to EBU standards.

foo_dr_meter: A simple Dynamic Range meter based on DR estimation formula published by https://dr.loudness-war.info/

foo_truepeak: ITU-R BS.1770-5 compliant True Peak scanner.

ReplayGain is part of the core components of foobar2000, so automatically adjusting the volume depending on the loudness of the trakc or entire album is pretty much a default feature of this player. The latter two components, especially the latter one give valuable insights into the loudness and mastering quality of a recording. True Peak can calculate the Peak-to-Integrated Loudness of a recording for example the headroom between loudest part and the maximum possible loudness of the format, or it tells you the loudness range in LUFS meaning how squished or wide the dynamic range of a track is. Really nifty if you have a huge music collection and need numbers to quickly compare releases.