[inlinevoid]

Try the "More languages" dropdown when selecting a language. I think its there near the bottom, but it's actually spelled in Japanese.

[slavik81]

It's also labelled as in beta. After signup, it clarifies what that means at the bottom of the page:

> Note: Readlang has only limited support for 日本語. Words are not prioritised based on frequency, and texts are not graded by difficulty.

Slightly disappointing, as I really hoped they did that, but I'll probably still give it a try. EDIT: I'm very impressed by the translation.