Alternative way of saying - What's up?

"What's up" can be said the other way,which is more formal.I don't think,it can be made informal. Its like:"What is going on with you?"

Hello LifeGuru. Well for me, “What’s up?” is fine though. I think when you use what’s up you need to vary your tone of voice on how you say it, and the intonation- so as not to make it sound informal. If you are not really comfortable on using what’s up to ask someone, you can go for “What’s going on?” “How are you doing lately?” “How’s life going on? Is everything okay?” questions like that.

Well another way would be: "Hey, whats going on" ... I think its not that informal and goes to any age.

Hi, LifeGuru. You can say it this way, so what is going on with you... That sounds more formal.

There are a TON of ways you can greet people other than saying "What's up?" You could say: "How's it going?" "What's going on?" "How are you?" "Glad to see you" "How have you been?" or you could even simply say "Hey!" But most of all, I think its HOW you say greeting is more important than WHAT greeting you say- if you put real emotion into what you say the words don't matter so much.

I can't think of many - How are you? How's life? How's everything going? Hope this helps. :)