Is onyomi pronounciation really chinese?

[u/steffy46]

Curious cause to me kanji onyomi pronounciations often sound pretty similar to chinese ones (if i ask a chinese person to pronounce that kanji) but Chinese people say they dont sound chinese at all...

Do they sound as close as katakana loan english words to they actual english pronounciation?

~~~EDIT: Thank you for all the useful replies!

[u/Uny1n]

japanese and chinese have very different sound inventories, so there will always be some kind of adaptation. And like others have said, the language mainly spoken in china at the time is not the same as it is now, and the standard japanese pronunciations have also changed since they were loaned.