Santa Claus, Easterbunny, Toothfairy

What's the right age to let your kids know, that Santa Claus, the Easterbunny and the Toothfairy are not real?

How to come out with the truth?

introduce the concept of parallel universes to them them at around age 6 then tell them that if they are bad children they will eventually wake up in a universe where none of those things existed and that they will have to pay half their check in taxes to some guy in a suit when they grow up just because it's funny. that will get them behaving for sure

You are actually seeking approval to destroy your own childrens' childhood fantasy world.
The answer is "NEVER !!"
If you don't grok this basic truth,I am genuinely sorry for you.

Valid question.Grok is a made-up word used in the novel "Stranger in a Strange Land". It means deep instinctive understanding.

Thanks for the answers so far.

@bunyip Just to clarify, I do not have any children yet.

The reason I was asking was, that a woman I know has a seven year old son who still believed in Santa Claus and got made fun of for it by his friends. And I was thinking that age seven is way too old to still believe in such things and that the parents had failed their son for not enlightening him sooner; sparing him the teasing from his friends.

Seems like a difficult decision to me. On the one hand it seems cruel to rip away their beautiful fantasy world, on the other hand it certainly is cruel too to let them embarrass themselves among their peers and allow them to become a laughing stock just because it is cute to keep them trapped in illusions for a while longer.

So I was curious what other people think, when is the right age to allow your children to know the truth.