YouTube, Spotify, podcasts, broadcast TV — every platform now normalizes to LUFS (Loudness Units Full Scale). Submitting audio without checking LUFS means your content is either too quiet or aggressively reduced by the platform's normalizer.
Why LUFS not peak
Peak normalization makes a loud song and a quiet song hit the same maximum — but they still sound very different. LUFS measures perceived loudness over time, matching human perception. Standardized in EBU R128 / ITU BS.1770.
Target levels
YouTube: -14 LUFS. Spotify: -14 LUFS. Apple Music: -16 LUFS. Broadcast TV: -23 LUFS. Podcasts: -16 to -19 LUFS. Mismatched: platform turns it down; if too quiet, listeners turn it up themselves (and your dynamic range gets hammered).
Measuring and adjusting
Tools: ffmpeg's loudnorm filter, EBU R128 plugins (in DAWs), online services. Two-pass loudnorm gives true LUFS-matched output. Don't trust 'normalize to peak'; it does the wrong thing.