The way we express laughter online as English speakers have evolved throughout the years. From the simple "haha", acronyms and slang terms emerged to signify different kinds of laughter. The acronym "lol", meaning "laugh out loud", has probably become the most ubiquitous slang term for laughter online. But there are others of its kind like "lmao" (laughing my ass off) and "rofl" (rolling on the floor laughing).
However, these terms are only limited to the English language. Other languages have their own ways of expressing laughter as well. For example, the Japanese way of typing "haha" is by using the character for grass, 草.
The reason for this is that the Japanese word for laughter is "warau" which was then shortened to just the first syllable or letter "w". However, people started noticing that "www" looked like blades of grass, and so they represented laughter by the kanji for grass. To take a bit further, for a bigger laugh, Japanese people would type 大草原 which means "a giant field of grass".
Turkish people have an interesting way of typing out laughter, by keyboard spamming. So, something like "asdfkhglkjlj" means that the person has been overcome by laughter because they could not form any coherent words or sentences.
Many of the other cultures simply type "haha" in their own languages like "jaja" in Spanish and Guarani, "ههههه" in Arabic, "χαχαχα" in Greek, and "חחח" in Hebrew.
A few interesting acronyms are "mdr" and "ptdr" in French which mean "mort de rire" and "pété de rire" and translates to "dead from laughter" and "exploded from laughter", respectively. And in Irish, "abmtag" which is shorthand for "ag briseadh mo thóin ag gáire," meaning "lmao". - via Atlas Obscura
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