"LOL" mean "laughing out loud", so it conveys the feeling that the writer truly finds what the other person said funny. But, hey! You don't necessarily cackle (synonym for laugh out loud) aaaall the time. When somebody says something you find amusing, you may chuckle ("reírse por lo bajo"), when somebody says something kind of embarrassing or revealing about you or that makes you feel uncomfortable, you will probably giggle ("reírse de forma nerviosa").
Anyways, busting out laughing -bursting in the BrE version- and benting over with laughter (again, synonyms for LOL) are great feelings to fully express in your daily life.
Till the next day, sing high as a Starling and let all those nice things in life make you smile.