What Does YouTube Do When Tracks Exceed or Fall Below the LUFS Target?

[drissa]

hello folks,

I’m trying to upload some of my mastered audio to YouTube and just wnna make sure I fully understand how it processes audio in terms of loudness levels. I’m assuming YouTube's loudness target is around -14 LUFS, so when I refer to numbers, they are related to this threshold.

1. What happens if my track is mastered at -6 LUFS? Will YouTube only reduce the volume, or will it apply additional processing? Does it reduce the whole track or just the sections that exceed the -14 LUFS threshold?

2. If my track is at -20 LUFS with peaks already hitting 0 dB, will YouTube boost the volume? Or will it leave the track at -20 LUFS since the peaks are already at the ceiling?

3. If my track is mastered at -14 LUFS but the peaks are below 0 dB, will YouTube make any adjustments? Will it leave the track as is, or will it make any changes?

4.What if my track is below -14 LUFS and peaks are below 0 dB? Will YouTube boost the volume to bring it closer to -14 LUFS, or will the track remain quieter than others?

5. Does YouTube only reduce volume if LUFS exceed the target? Will it ever boost quieter tracks, or does it only reduce louder ones?

Thank you, everyone! I know it’s a lot of questions, but I’m genuinely trying to learn and understand this better.

[WackyZoundz]

1. What happens if my track is mastered at -6 LUFS?

It will play back at -14 dB LUFS so roughly less than half the volume.

2. If my track is at -20 LUFS with peaks already hitting 0 dB, will YouTube boost the volume?

Yes. There is a headroom to make sure there will be no distortion. I don't know how much headroom because YouTube keeps changing its algorithms constantly but it's large enough.

3. If my track is mastered at -14 LUFS but the peaks are below 0 dB, will YouTube make any adjustments?

No.

4.What if my track is below -14 LUFS and peaks are below 0 dB?

Replay gain is applied to reach -14 dB LUFS.

5. Does YouTube only reduce volume if LUFS exceed the target? Will it ever boost quieter tracks, or does it only reduce louder ones?

It does both to give the listener a (more or less) constant experience.

[WackyZoundz]

It should be noted that LUFS is only used for replay gain, the upload isn't changed in any way (aside from compression). You can test this by downloading videos and analyzing them, you will see that their volume is all over the place (Both peak and LUFS). You don't have to worry about your upload getting limited.

[mjolnir]

good answers to good questions.