Was Nietzsche really an existentialist?

Nietzsche is largely considered to be one of the fathers of existentialism. He tried to develop a theory of human meaning in a universe which appeared to lack any. Ever since, this has been the core tenet of existentialism - finding meaning in an absurd or apparently meaningless existence. Niethzsche thought that meaning could be found through an aesthetic existence - living one's life as though it were a work of art.

So yes, I'm inclined to say that Nietzsche was really an existentialist since he created (along with kierkegaard) the core pratice of existential philosophers ever since: trying to find meaning in an apparent meaningless existence. This seems to be the main criterion of being an existentialist philosopher.

"why he was considered a existentialist writter" cool. uh, existentialism is easy. it's the question of existence, why do we exist, how do we exist, what makes us exist, etc. Existentialists believe this is what philosophy should focus on. Obviously, Neitzsche is considered an existentialist because he wrote about that. That's why he was an existentialist: much of his writings deal with existentialism. If you're looking for specific examples, you can probably just search up quotes. but that solves the why-- he was because he was. (philosophical answer ftmfw!)

He was a nihilist who believed that institutions like governments and religions were inherentlly flawed and corrupt. He wasn't an existentialist as he died in 1900...well before existentialism was formed as a philosophical movement in Europe.

Not really. He had some existential tendencies, but mostly he was just a chaotic sociopath. Of course, existentialism isn't so much of a philosophy as an anti-philosophy of deciding unanswerable questions aren't worth dwelling on, so it's hard to find professional philosophers that are -- even Sartre had to find something different to think about later in his life. Camus didn't, but he died rather young.

He was a Nihilist....... quite different from an existentialist.

I think that Nietzsche was more of a nihilist.

Yes, I am inclined to agree with the above answer.