XSWL is Chinese slang meaning basically the same thing as LMAO.
It's comprised of the characters 笑(xiào)死(sǐ)我(wǒ)了(le
A texting conversation

Person1: Ever since he feel into the bin last year everyone's been calling him bin boy.

Person2: xswl

Person2: So funny
by DoorHandle1234 August 22, 2017
It's a word which'laughed me to death'. This is a word from China, it comes from the Chinese Hanyu Pinyin, and since Hanyu Pinyin uses English, XSWL is the initial letter of each Chinese character Hanyu Pinyin.
Xswl,he said he could fly .
by Stephen Kwal January 9, 2023