I am curious that why there are some websites that chrome can translate automatically to the chosen language while it cannot to others?
I have tried using several extensions but the website is not getting translated. Is there any possible explanation for this?
Having a link to a particular case will help greatly but I can try to answer the general case. There are two main reasons:
The first is obvious so let me explain the second one. Chrome detects the webpage language using heuristics. They are in a package known as the compact language detector (CLD). It is compact, which means it trades database size for accuracy; the non-compact, more accurate version being many times larger.
So assuming that the page in question is in a popular language, there must be something in the sequence of text characters that is confusing the CLD which either does not know what language the page is using or it thinks is using a language that Google does not know how to translate.