In a word, yes! Or, if you like:
Because Diffbot APIs rely on computer vision, they tend to do very well identifying similar elements from pages in most languages. We also supply our algorithms with training data in multiple languages, so as to better identify linguistic and other differences.
The returned data will be in the original language. Which language it is will be specified in the
humanLanguage field. See the API reference of each individual API to find out more.