What is the difference between 夸张 and 过分
夸张 (kuāzhāng) simply means Hyperbole, Exaggeration. 

As in, your friend told a story that was too 夸张... 

你朋友的故事太夸张了 - your friend's story is a bit exaggerated...

Or if someone is acting ridiculous, crazy, or flamboyant (in a funny way, not in a mean way), you could say they're acting 夸张.



过分 (guòfèn), as you can tell from the two characters 过 (overstep), 分 (portion, point)... that they've overstepped their points/ or overstepped their boundaries. 

你朋友干吗打我？ 他太过分了。。。 - Why did your friend hit me? He went a bit overboard...



Something helpful for me... 

When the translations of words are similar (in the case of 夸张 and 过分), it always helps to break the word into parts as I described above. That helps for two reasons:


It gets you familiar with the individual meanings of characters
Makes you more self-sufficient with learning the language as you can dissect each meaning when given ambiguous translations