Batman is honestly scarier than Superman. The Dark Knight is the world's greatest detective, a warrior at peak human physique, a genius, a billionaire (as Bruce Wayne), and he isn't afraid to get dark and gritty to take down any bad guy.
Trust and believe, Batman stays packing with gadgets, but his greatest gadget in a fight against Superman is Kryptonite. With enough Kryponite and other gadgets to at least slow Supes down, Batman would easily win.
Superman is a basically a God from another planet. Batman might be cool, rich and a master fighter, but he's only a man. There's not enough Batsy body armor in the world that could stop Supes from annihilating him with his heat vision, superhuman strength or flight. Luckily enough for Batman—Superman would never do that. He fights fair, which is saying a lot because there aren't many on his level.