Gabi

As a Hungarian name, it’s also a diminutive of Gabriella.
https://www.behindthename.com/name/gabriella

Very common nickname for Gabriel/Gabriela in Brazil as well, usually with a slight change in pronunciation depending on the gender of the person. For boys, it’s always “GAH-bee”, and for girls it’s either “gah-BEE” or “GAH-bee”, though the former is much more common. As a Gabriela myself, I go by “gah-BEE”, but I’ve had many people call me “GAH-bee” when we first meet! [noted -ed]

Also common in Israel as diminutive of Gavriel. I'd even go as far as saying that most men whose name is Gavriel go by the name Gabi (though I don't have statistics on this). One famous bearer is former chief of staff, Gabi Ashkenazi.

Also Spanish. [noted -ed]

It's also used in Spanish. I knew a girl from Peru with this name.

In Germany Gabi is also a nickname for girls named Gabriele. [noted -ed]