Loudness normalisation explained: why mastering to -8 LUFS gets turned down on Spotify

If you master a track to -8 LUFS so it sounds as loud as the big releases, most Spotify listeners will never hear that loudness. Spotify adjusts tracks to -14 dB LUFS during playback, measured with the ITU 1770 standard. On the default setting, that -8 master gets turned down by about 6 dB (our arithmetic: -8 minus -14). It ends up at the same level as everything else, minus the punch the limiter took out.

This guide covers what Spotify documents, how Apple and YouTube differ, and how to use that when you sign off a master.

What does Spotify actually do to your track?

Spotify's loudness page for artists is unusually specific:

• It measures, it doesn't re-master. Loudness is measured when you upload, and gain is applied while the track plays. Your file isn't processed before playback.
• Loud masters get negative gain. They are turned down to -14 LUFS, which Spotify says adds no distortion.
• Quiet masters get positive gain, but only up to a point. Spotify takes the track's headroom into account and leaves 1 dB of headroom for lossy encodings. Its own example: a track at -20 LUFS with a true peak of -5 dBFS is lifted only to -16 LUFS. That is a 4 dB lift, which puts the peak at -1 dBFS (our reading of the numbers).
• Albums are treated as albums. A full album is normalised as one unit, so quiet tracks stay quiet relative to loud ones. On shuffle or in a playlist, each track is adjusted on its own.
• Premium listeners can change the target. Loud is -11 LUFS, Normal -14 and Quiet -19. On Loud, Spotify sets the level regardless of true peak and uses a limiter that engages at -1 dB, with a 5 ms attack and a 100 ms decay.
• Not everywhere. The web player and third-party devices such as TVs and speakers don't normalise.

What true-peak level should you aim for?

Spotify's mastering tips are to target -14 dB integrated LUFS and keep true peak below -1 dBTP, which it says suits lossy formats (Ogg/Vorbis and AAC). If your master is louder than -14 LUFS, keep true peak below -2 dBTP, because louder tracks are more likely to distort when encoded. The same rules apply to lossless delivery, and you send one stereo master per track. For more on delivery formats, see our guide to what to deliver for Spotify Lossless.

Spotify's troubleshooting page adds two points most mastering guides leave out. First, ITU 1770 applies no lowpass filter, so inaudible high frequencies can make the meter overestimate loudness, and your track gets turned down further than it should. Second, very loud masters with true peaks above -2 dB can distort during encoding. That distortion can make a track seem louder without improving it.

How is Apple's Sound Check different?

Apple's Digital Masters guide describes Sound Check in the same terms. It measures each track's loudness, stores the value in metadata and uses it to raise or lower playback volume. It can also work per album, so albums that depend on level changes between tracks keep them. Apple says plainly that loud masters will play back quieter and can "actually sound weaker". It also recommends at least 1 dB of headroom, because oversampling during playback can clip a signal that sits at 0 dBFS.

What Apple doesn't publish in that guide is a target number. The widely quoted -16 LUFS comes from mastering engineer Ian Shepherd, who reported in March 2022 that Apple had moved Sound Check to LUFS, was normalising to -16 LUFS, and had switched it on by default for new installs. That is a well-informed secondary source, not an Apple statement, so treat -16 as a reported figure.

Listeners control it themselves. On iPhone, Apple's user guide has you open Settings, tap Apps, then Music, where Sound Check sits next to EQ with the line "Normalize the volume level of your audio".

And YouTube?

YouTube publishes the least. Its Help Centre has no music loudness target that we could find. What it does document is Stable volume, which is on by default and continuously adjusts levels to narrow the gap between quiet and loud passages. In our reading, that is closer to compression than to a single gain offset. Crucially, YouTube says this feature is turned off for YouTube Music and official music videos.

Creators also have a channel switch. In YouTube Studio on a computer, go to Settings, then Channel, then Advanced settings, where a box reads Let YouTube enhance audio quality. YouTube says audio enhancements can include automatic volume and mix adjustments, and that the setting only affects future uploads.

For normalisation itself, the most detailed public explanation is again Ian Shepherd's, from 2017. On desktop, right-clicking a video and opening "Stats for nerds" shows a content loudness figure. A positive value means YouTube turns the video down by that amount, and it doesn't turn quieter videos up. That is nine years old and not from Google, so check it on your own upload rather than relying on it.

How to make the mastering decision

1. Master for the sound first. Pick the loudness at which the track sounds best, not the loudest level you can reach.
2. Read integrated LUFS and true peak on a meter that reports both, for the whole track.
3. Work out the Spotify offset. Subtract -14 from your integrated LUFS. A positive result is how much Spotify turns you down on Normal. Then check the Loud (-11) and Quiet (-19) cases too.
4. If you're quieter than -14, check your true peak. Spotify only lifts you until the peaks reach about -1 dBTP, so a quiet master with hot peaks stays quiet.
5. If you're louder than -14, bring true peak under -2 dBTP.
6. Check the top end. Inaudible high-frequency content inflates the measurement.
7. For albums, set the level relationships between tracks deliberately. Spotify and Sound Check can both keep them in album playback.
8. Upload one video to YouTube unlisted and open Stats for nerds to see what it reports.

Checklist before delivery

• Integrated LUFS noted, and the Spotify offset worked out for Normal, Loud and Quiet
• True peak at or below -1 dBTP (-2 dBTP if louder than -14 LUFS)
• No ultrasonic junk inflating the meter
• One high-quality stereo master per track
• Album sequence levels checked in full-album playback
• YouTube Studio audio-enhancement setting chosen before upload

If you're weighing an automated master, our look at AI mastering against an engineer covers how those tools set loudness.

What we think

In our view, normalisation has ended the loudness war on the players that use it, and few artists have caught up with what that means. A -8 LUFS master no longer wins on loudness. It loses on dynamics and then gets turned down to the same level as a -14 master. Spotify's own troubleshooting page spells out the consequence: a dynamic track and a loud one play at the same perceived level, and the dynamic one's peaks can feel louder.

That doesn't make -14 a rule. Spotify presents it as a tip, and dense genres may still choose a hotter sound on purpose. The real gain is freedom. You can now master to taste, and the platform evens out the level.

Two things work against artists. First, the platforms don't agree. Spotify documents its numbers in detail, Apple's guide documents the method but not the target, and YouTube says almost nothing about music loudness. Independent artists end up relying on one engineer's blog posts to fill the gaps. Second, the web player and many TVs and speakers don't normalise at all, so, by our reasoning, a quiet master can still sound quiet there next to a loud one.

Our ask to Apple and YouTube is simple. Publish the target, the peak-headroom rule and the album behaviour on one artist-facing page, the way Spotify does. Mastering decisions shouldn't depend on guesswork about how a track will be played back.