What’s the best way to tell a girl that you aren't interested going out?

Yeah please dont ignore her this will hurt her more than when you will tell frankly that you dont want to be more than her friend. You can explain to her that you dont want to lose a friend like her and that if you go out with her and this relationship does not work you will then definitely lose her friendship so its better to be remain just friends.

Be honest with her. Just say that u like her alot as a friend and that u do not wanna risk your friendship at all. Tell her that u think of her as a sister and that u wish to always have her in your life as a friend.

Best thing is to be honest with her. And do it sooner rather than later. Be firm that you will not change you mind either. It will hurt her but she will get over it. I used to be afraid to hurt a guys feelings and I would put it off and not say anything and then kinda try to worm my way out of it but they just held on to any little bit of hope I gave until I had enough and said no way never gonna happen. It hurts more to be gentle cause they think you really do care and maybe another time things could be different. Be firm but say you really like being friends and would like that to continue. However if she anything like the guy friends I had who really wanted a relationship. When she accepts that you don't want a relationship she will be on to the next guy fast.