While watching "funny Boruto moments" on YouTube, I came across a scene where Naruto tells Iwabe and his team, that he that he is still a Genin, but he is a Hokage. In the starting episodes of Naruto, it is shown that Hokage is a rank above Jonin, so I want some clarification on why he could skip all the ranks and land at Hokage.
He is still a Genin. It was stated by him. (Episode 48)
What people most of the time overlook is, that the scene with Kakashi and Naruto isn't actual canon though, it should still be noted that these are the requirements. But we're talking about Naruto here he doesn't do things the normal way, which is important later on with the Kishimoto bit.
If we look into the databook book specifically for The Last: Naruto the Movie that plays 2 years after the 4th war, Naruto is still a Genin. 下忍 = Genin.
Sakura and Shikamaru on the other hand are already Jōnin. 上忍 = Jōnin.
And the rest are Chūnin. 中忍 = Chūnin.
Kishimoto specifically let Naruto stay a Genin. And yes, TheLast is canon. He did the character designs and was chief story supervisor. It was also the first time for him that he'd completely written everything from the start, including the lines in a movie production. That came up during the Interview that is linked.
He confirmed that Naruto went from Genin to Hokage.
Q: Speaking of Naruto, his dream of being Hokage came true, but when did he take the exam to become a jounin?
Kishimoto: Naruto didn’t become a jounin. He became Hokage as a genin. Sasuke is not a jounin or chuunin either, but rather, since he left the village, he is a nukenin. That’s enough for them (laughs). But I thought that having him suddenly go from genin to Hokage would be amusing and Naruto-like.
Even if he never achieved the Jōnin rank he should be as smart and as capable of Chūnin and Jōnin. People can't just become Hokage, not even Naruto. He must have still learned everything that needs to be learned for the Hokage position but just didn't get the chance to actual showcase this in the exams. But I don't think he needed to, I mean everyone (at least the Shinobi part of the Village) saw him during the 4th war and his prowess/abilities. The only thing that was missing was the educational part.
Well, according to Kishimoto, Naruto became the Hokage as a Genin. That should answer it.
Naruto had a Jounin title before he took up the Hokage title.
What a lot of people get wrong is the Hokage title. It is not only a rank, but also the title given to the leader of Konoha. Each Hidden Village will have a ruling Kage, but also have predecessor Kage (retired). A person could be classified as Kage level, but it is not a rank. It is the scale of power that Shinobi has.
Every Hokage, after Tobirama, before taking up the mantle was a Jounin. It is the custom and tradition of Konoha to appoint a leader who is not only powerful, but wise and collected. He should have a great deal of knowledge regarding major governing factors of the village.
This was the reason Kakashi, after the Great War, offered Naruto the Jounin rank. Of course, with conditions. That would include more studying. Naruto comically declines, but Iruka sensei helps him out (Naruto: Shippūden episode 479).