EBU R128 is the European Broadcasting Union's loudness recommendation, the rulebook that made consistent loudness normal across European television and much of streaming. It builds on the ITU-R BS.1770 measurement and sets concrete targets: -23 LUFS integrated loudness with a tolerance of +/-1 LU, a true-peak ceiling of -1 dBTP, and constraints on Loudness Range (LRA). Crucially it normalizes by program loudness rather than by peak, which is what finally stopped commercials being mixed louder than the show. Its companion specs (EBU Tech 3341-3344) define the meters and gating, so any compliant tool measures the same number the same way.
