As btn said, the Japanese page is "flatter", there's more information directly on the page, things are stated more explicitly, with fewer abbreviated forms and much less stuff hidden behind tabs or links.

In general, however, I think Japanese tends to be a fair bit more information-dense than English for a given amount of space/characters. It can vary greatly, depending, for instance, how polite you're trying to be, how many foreign words you use, etc, but the ideographic core is very, very, dense compared to English.

[A point driven home by trying to write text messages in Japanese versus English... my experience is that it's much harder to cram in what you want to say into the given limits (~160 bytes) in English, despite Japanese characters using multiple bytes each...]