What is the similar to - it all Greek me in Spanish language?

The closest equivalent to "It's all Greek to me" in Spanish is:

"Es chino para mí."

This literally translates to "It's Chinese to me," and conveys the same sense of incomprehension and confusion.

Here are some other options, depending on the specific context:

* "No entiendo nada." - "I don't understand anything." (More direct and general)

* "Me suena a chino." - "It sounds like Chinese to me." (More idiomatic and humorous)

* "Para mí es un misterio." - "It's a mystery to me." (More formal and mysterious)

Ultimately, the best translation will depend on the specific situation and the level of formality you want to convey.