Ssj4 is indeed an incredibly powerful transformation and as we went over before is even more powerful than than any form of Goku in DBS, yes that includes ultra instinct and no DBS Goku isn't universe level or any of that shit.

The reason I didn't go over ssj4 Goku when doing GT Goku vs Super Goku is due to the fact that by the time we made it to the beginning of Gt GT Goku had already won so SSJ4 would just be overkill. However now we have enough time for focusing on Goku alone, so let's find how powerful is SSJ4 Goku truly is.

So the best thing to mention before beginning this analysis is GT takes place in the same canon as the movies and non canon episodes. This is evident from the fact that Cooler is in GT.

Which connects the movies to GT, Pikkon is then in fusion reborn connecting non canon episodes to the movies.

From this we know that we can indeed use Frieza's solar system level feat in the anime.

If we then go down to the cell saga from this, since we calculated that Cell is 6,400 times more powerful than Frieza that makes Cell saga toie Goku is multi solar system level.

Later Base Goku scales to pikkon who wrecked super perfect Cell.

https://www.youtube.com/watch?v=hRkc5c-A_TU

If we low ball this and just say base Goku at this point equals super perfect Cell and say super perfect Cell is 2 times stronger than perfect Cell who scales to cell saga super saiyan Goku that would make base Goku in the pikkon arc 12,800 times solar system level.

Now let's go over speed for this. I already explained how base Frieza Saga Goku is 389,300.41 x faster than light. This makes super saiyan frieza saga Goku 19,465,020 x faster than light.

Now then we know cell saga super saiyan Goku is 6,400 x stronger than ssj goku in the frieza saga.

This makes base Goku in the pikkon saga 124,576,131,200 x faster than light, over a billion times faster than light.

Moving to the Buu saga it's clear that kidd buu is indeed galaxy level.

This is shown from when Buu destroys the earth and the resulting explosion should be around galaxy level by scaling to the galaxy in the background.

From this we can find how fast Buu and therefore ssj3 Goku are by scaling how much of a power difference this is since in dragon ball the more powerful you become the more your strength and speed increases. There are at least 100 billion solar systems in a galaxy and earlier we found pikkon saga goku is 12,800 times solar system level.

Therefore base Goku when he fought uub at the end of 7 is over 7 million times stronger than base goku in the pikkon saga.

That puts Goku here at over 900 quadrillion times faster than the speed of light!!!

Now broku while going through all of gt at the end of his scaling got gt goku to be 5 septillion times more powerful than he was at the end of Z and while the scaling and all is fine the only problem is that would put ssj4 goku at over treddellion times faster than light which is far beyond anything we've seen in the series, it would also make gt goku multi universe level when the best we see is mid to high multi galaxy.

So if we put in the multipliers including Broku's 250,000 x multiplier for super saiyan 4 we get ssj4 goku as being multi galaxy level and over SEPTILLION TIMES FTL (though again that's never really backed up, something like quadrillion or quintillion is a good bit more likely)

This is why Ssj4 vs ssj blue really doesn't work, without those "universe level feats" dbs Goku is only really at most galaxy level and trillions of times faster than light which is nothing in comparison.

Overall that is how powerful Ssj4 Goku truly is, hope you all enjoyed