Righteous3Demo is a universal binary Audio Unit plugin for the 2-buss, and it is the first and only plugin that can do loudness maximization on YouTube AFTER they put in their ‘replay gain’ function.
At the time of writing I don’t have the full version of this plugin: this is still the demo :(
And it does it perfectly honest and legit, too, by delivering what Google wants: but optimized. It was originally designed to force people to mix dynamically, at a lower target level than YouTube’s -13db RMS. (it’s now adjustable, so if they change it you can retarget!)
It was originally designed as a final output stage for targetting Pono, so it has an Airwindows fancy wordlength reducer set to 24 bit for such use (or any 24 bit export). It uses Naturalize out of Ditherbox, which is a $50 value already. It also includes a simplified version of Airwindows ADClip 4, without the techniques for sneaking clipped bass and treble energy back into the sound, and without the fancy bypassing when not actively clipping. That’s okay, all we really need is to soften the onsets and exits of clipping energy (most obvious at 44.1 or 48K)
And now with Righteous3, you can morph between the tighter, more well-behaved performance of Righteous2 and the luxurious bloom of the original ‘mix everything super quiet’ Righteous, with the Asymmetrical Bloom control! Turn it up to get more lushness and bass warmth, cut it back to rein in things if you’re pushing Righteous3 a little harder.
And finally, Righteous3 has opened things up to all sorts of workflows, not just the super-idealistic focus of the original Righteous! Use 24 bit to produce your hi-res output. Switch it to 16-bit and output CD-optimized audio using the same Naturalize dither (exclusive to Airwindows). Or, set it to 32 bit and get the same noise shaping to the CoreAudio buss that all the Purest series of plugins use, so you can use Ditherbox or ADClip or literally any other mastering-type plugin you wish! The stuff Righteous brings to the table is too important to restrict it to just one workflow. You can have everything Righteous was designed to be, or you can swap in anything else you like!
By the way, just because you CAN use Righteous3 to maximize YouTube loudness (no matter what they change: just target the RMS level they want you to hit) doesn’t mean you should. -13db is by no means obnoxiously overloud, but you can still allow for more open and dynamic sounds. You might like them! -13db is probably your best bet for not having your balances altered by YouTube, though.
Righteous3 is $50.