By statements and part 1 stats, they’re equal. But this is a retcon…if we look at feats and scaling, Itachi is more powerful than Jiraiya.
Itachi is around EMS Sasuke’s Level
Itachi was a spy, he only wanted to protect the village. This is confirmed by Obito, kabuto, Hiruzen, Danzo and Itachi himself. That's why he disengaged a lot of fights and didn't kill anyone despite having so many opportunities to do so. Even kakashi questioned why he let him live. (In the novels tsukuyomi is capable of killing someone) He didn’t capture Naruto in the hotel or forest when he had him alone. Too many coincidences right? This is why
Now that we confirmed Itachi is a spy that was holding back. And debunked that statement Let’s get into his feats
Itachi casually one shot Jiraiya’s lifelong rival multiple times. Orochimaru left the organization in shame and fear. The same guy who is stronger than base Jiraiya.
he one shot deidara
He one shot the multi headed dog that Jiraiya fought for an entire episode. And the 8 headed serpant which was Orochimaru’s strongest Jutsu. He can deal with any summonings, for example sasuke could put manda in a genjutsu with a 3 tomoe Sharingan in less than a second so imagine itachi
He one shot nagato (with assistance) and defeated Kabuto, a perfect Sage (with assistance) who both are leagues above Jiraiya
itachi figured out the rinnegan eyes were linked and he disabled nagato's vision by using blind spots. Proving his intelligence and that he can deal with The rinnegan. He's so fast that part 1 Kakashi, Hebi Sasuke, Kabuto & controlled Nagato could not read his hand signs.
Kabuto had the powers of Orochimaru, the sound five, jugo, Suigetsu and many others. Itachi held back against him and pretty much carried the fight despite Sasuke being there.
A Massive Rasengan can’t break a base Susano, Jiraiya also needs to be in Sage mode to use such rasengans.
It takes an entire episode to go into Sage mode and Itachi finishes his fights very quickly shown throughout the manga and novels.
Though his stamina is not as bad as people think, even sick, dying and half blind he has more stamina than Hebi sasuke as they both collapsed at the same time.
Sound genjutsu only works in locations like a cave or the corridor/tunnel pain was in. itachi is faster than sound and can see the chakra waves in the air. He can take out ma and pa as he see’s them building up chakra with his dojutsu like pain did. Even Temari could counter sound waves with her fan in part 1 and Sasuke could outrun sound waves during the forest of death with his cursemark.
Itachi would beat base Jiraiya medium diff and Sage mode Jiraiya high to extreme diff.