What does lit AF mean?

“Lit”on social media means “cool or awesome” And AF when elaborated means “as f***” So in simple sense a person could meant “Lit AF” as “extremely cool or awesome

What does AF mean on Facebook?

When someone writes af (either capitalized or in lowercase letters) on social media or in a text message, it simply translates to as f***. You fill in those asterisk symbols with the rest of the letters. F*** is not exactly a polite word!