I’ve always considered that texting “hehe” is a light chuckle, a “heh heh” sound; “hehehe” is more of a giggle, whether coy or creepy; and any more “he”s than that delves into witchy cackling territory.
But “haha”, “hahaha”, and “hahahaha”, all “sound” the same to me and the meaning only varies in intensity but is more context dependent.
By number of ‘hehs’:
1-2: situational ranging from genuine to sarcastic to ‘funny but not haha funny’
3-4: “got’Em”
Hehehehehe: devious
Anything past that is a chuckle on its way to laughing.