Loudness normalization means the player measures each track's integrated loudness in LUFS and changes its playback level to match a reference. Spotify uses −14 LUFS on its default setting, Apple Music about −16 LUFS, YouTube, Tidal and Amazon Music about −14 LUFS and Deezer about −15 LUFS. A −8 LUFS master and a −14 LUFS master then play at the same loudness on Spotify. For listening, leave it on so tracks don't jump in level. For judging your own masters, leave it on too, because that is how most listeners hear them.
How loudness normalization works
The service measures the integrated loudness of the whole track, using the ITU-R BS.1770 method. Integrated loudness is gated, so silence and quiet gaps don't pull the reading down. The service then works out the difference from its reference level and applies it as a gain change on playback.
- A −9 LUFS track on Spotify is 5 dB over −14 LUFS, so Spotify turns it down 5 dB.
- A −14 LUFS track plays unchanged.
- A −17 LUFS track is 3 dB under. Spotify turns it up 3 dB only if its true peak stays under −1 dBTP afterwards, so its peaks would need to be at −4 dBTP or lower.
Normalization doesn't compress or limit the track. It moves the whole track up or down by one amount, so the balance inside the track stays as you mastered it.
Loudness normalization on Spotify
Spotify publishes its rules in full, so it is the clearest case. It has three settings.
| Setting | Reference level |
|---|---|
| Loud | −11 LUFS |
| Default | −14 LUFS |
| Quiet | −19 LUFS |
On the default setting Spotify turns loud tracks down and can turn quiet tracks up as far as their peaks allow. When you play an album, Spotify normalizes the album as a whole, so a quiet interlude stays quieter than the loud song after it. Listeners can switch normalization off in the app's settings.
Other services
YouTube turns loud tracks down to about −14 LUFS and never turns quiet ones up. Apple Music calls its normalization Sound Check and uses about −16 LUFS. Tidal and Amazon Music sit at about −14 LUFS and Deezer at about −15 LUFS. Only Spotify publishes its rules in full, so treat these as estimates. Instagram, TikTok and SoundCloud publish no loudness target for music. The LUFS for streaming guide covers each service.
Loudness normalization on or off?
The answer depends on what you're doing.
As a listener, leave it on. With normalization off, every track plays at its file level, so a −8 LUFS master plays 6 dB louder than a −14 LUFS one and you reach for the volume between songs. Turn it off only if you want to hear masters at the level their engineers left them.
As a producer checking a release on Spotify, listen with it on first. Most listeners keep the default, so that is the level your track will play at next to others. Then switch it off once to hear the file as delivered, which is how it plays for anyone who has turned it off.
When you compare your own mixes or masters, normalize them yourself. Two versions that differ by even 1 dB won't sound equal, because ears hear the louder one as fuller and brighter. Turn every version down to the quietest one before you judge. That is level matching, and it is the same thing a service does, done for your test. In ABSeq, Auto Gain does it for every loaded track, measuring each file's integrated loudness and turning the louder ones down to the quietest.
The loudness war
Before normalization, a louder master played louder. Put two songs side by side and the louder one sounded fuller and brighter for that reason alone. So masters got louder over time, through more compression, limiting and clipping. Each extra dB of level came from shaving down the loud moments, which left less difference between the loud and quiet parts of a song.
Normalization removes the payoff on the services that use it. A −8 LUFS master on Spotify's default setting is turned down 6 dB and plays at the same loudness as a −14 LUFS master. The listener gets no extra level, only what the extra limiting did to the sound.
Loud masters haven't gone away. Some music is meant to sound dense, and density is a sound you can choose. A loud master also still plays loud wherever there is no normalization, such as Spotify with the setting switched off. The difference is that loudness is now a choice about sound, not a race for level.
What it means for dynamic range
Dynamic range here means the difference between the loud and quiet moments of a track. Loudness range (LRA, in LU) is one way to measure how much the loudness varies across a song.
Normalization doesn't add dynamic range back to a heavily limited master. It only turns the whole thing down. But it stops penalizing masters that keep their dynamics. Take a −13 LUFS master and a −8 LUFS master of the same song. Spotify turns the first down 1 dB and the second 6 dB, and they play at the same loudness. The −13 LUFS one went through less limiting, so its drums and choruses keep more of their lift.
A quieter master isn't penalized on services that only turn tracks down. It does play quieter than other tracks anywhere it isn't turned up. To choose a level for your own master, see how loud should my master be.
Questions
Should loudness normalization be on or off?
For listening, on, so tracks play at about the same loudness and you don't adjust the volume between songs. For checking your own release, listen with it on first, since that is how most listeners hear it, then once with it off to hear the file at its own level.
How does loudness normalization work on Spotify?
Spotify measures each track's integrated loudness and plays it at −14 LUFS on the default setting, −11 LUFS on Loud and −19 LUFS on Quiet. It turns loud tracks down and turns quiet ones up only as far as the peaks allow, keeping them under −1 dBTP. Albums are normalized as a whole when you play an album.
Does loudness normalization change the sound of my master?
No. It changes the playback level by one amount for the whole track and doesn't compress or limit it. The balance inside the track stays as mastered, but because ears hear quieter playback as less full and bright, a master turned down several dB can sound smaller next to its file level.
Did loudness normalization end the loudness war?
It removed the reward on services that normalize. A −8 LUFS master on Spotify is turned down 6 dB and plays at the same loudness as a −14 LUFS one, so the extra level is gone and only the effect of the extra limiting remains. Loud masters still exist, as a choice of sound rather than a way to play louder.
Does YouTube normalize loudness?
Yes. YouTube turns loud tracks down to about −14 LUFS and never turns quiet tracks up, so a master under −14 LUFS plays quieter than louder tracks there.