* χαχα (χαχαχα for a longer laugh): This is the most common and closest equivalent. It's a phonetic representation of "haha" (or "hahaha"). It's widely understood and used online.
* 😂 (emoji): Emojis are universally understood and frequently used, just like in English.
* (Γελάω): This means "I laugh" (γελάω - gelao) and is a more formal way to express laughter. It's not typically used in the same casual way as "lol".
So, χαχα is probably your best bet for a quick, informal equivalent of "lol" in Greek.