"he laughed his heart out!" or "he laughed his head off!"
When intending to express that somebody laughed very loudly and for a long time, what is the proper expression to use?
"he laughed his heart out!" or "he laughed his head off!"

thanks for all of the advice

Question

"he laughed his heart out!" or "he laughed his head off!"
When intending to express that somebody laughed very loudly and for a long time, what is the proper expression to use? 
"he laughed his heart out!" or "he laughed his head off!"

thanks for all of the advice

Answer

Like Robert, I have never heard anyone  say 'He laughed his heart out'.  It sounds like a translation from another language, or a something a foreign learner would say by analogy with 'He cried his eyes out'.

When I googled it, all I found was one source, an 'inspirational' rhyme beginning 'Laugh your heart out, Dance in the rain'.  That's all.

'Laugh one's head off' is a common idiom. 'Laugh one's heart out' is not an expression which any native speaker would use.

Answer

I'm American/Australian, and I've never heard of "he laughed his heart out." So to me, the other one is the only choice.

Answer

In my opinion they are both correct. These expressions are very similar.

Answer

I havent heard "laugh my heart out" i think he better phrase would be: "he laughed to his heart's content"  
"He laughed his head off" is correct  a other way to that is: "he was cracking up!"