I have never gotten a tattoo before (although I want one), I do have my belly button pierced, though! I literally did so much research on the pain and all that, and when I got there, I was so so nervous it was going to hurt like crazy, but it didn't! Literally, I did not even feel when he shoved the needle through, haha. Honestly, it was just pretty sore after I got it done. And if you knocked into anything or got it snagged on your shirt or whatever, it hurt. But once it is fully healed, its like you don't even notice it is there anymore. I say go for it! I know everyones pain levels are different, but honestly, it was not bad at all!
uhh I don't know.. tattoos and piercings are two totally different pains. i think overall a tattoo would be more painful, because it can last a few hours. a belly button piercing is pretty quick. it's a quick pinch and it's not bad at all. maybe a 4-5/10. afterwards it's just a little sore and throbby but that's to be expected.