“Jarvan IV will almost always beat you early on thanks to his attack speed boost from his Demacian Standard (E). Avoid fighting him.
Once you get your Red Smite you can beat him in duels. Keep avoiding him if you built Blue Smite.
Jarvan IV can get fairly intimidating late game if he got himself a Warrior's enchantment but you should still be able to beat him with your form. If you are playing Rhaast and he decides to go Cinderhulk he will serve as a great HP reset target.”
“If he gets ahead and build damage, he may one shot you, so be careful and keep your ult when invading him”
“Jarvan is pretty decent against tanks. His passive auto attack is quite strong against Sion and his E->Q combo will easily cancel your Q. His ult can also easily stop your ult. To win this matchup you just need to wait for him to make a mistake. If he E->Q's on you and misses or doesn't cancel your Q then he has no way of escaping and will be very vulnerable. A small tip, although maybe not practical is that if you are ulting and Jarvan wall is right infront of you, cancel your ult. If you timed it right you will jump over his wall which can be useful if trying to escape or chase him.”
“As long as your lanes don't int to his lvl 2-3 ganks, you powerfarm into moon and outscale.”
“J4 is difficult to deal with at almost every aspect of the game. He will out trade you every time early game unless he has very low health and you come across him out of position. You need to be extra careful that he doesn't invade your first buff as sadly you will die without some help from your team. Later in the game, once you have some items he becomes a bit more manageable but can still be an issue. He can easily lock you down with his ulti and cc you pretty hard.”
“J4 is difficult to deal with at almost every aspect of the game. He has strong early damage and gank potential. Depending on his build J4 can have the ability to one-shot you. If you can avoid his knock-up (E)+(Q) Combo you will have a good chance to beat him in a 1v1.”
“Easy to invade but annoying to catchup to w/o bushes ”
“Jarvan is quite easy to kite. You can hop over his ultimates wall. You can also dodge his eq with your q.”
“J4 is a easy matchup for you, when he jumps on you just try to dodge with your E, if he ults you press your ult, he has no chance to kill you, so don't worry, you should be really ok (unless he's ahead or you're low hp).”
“Jarivan not only has gap closers but will be able to destroy you in 1v1s.”