Japanese Highlighter

Japanese Highlighter highlights rare Japanese dictionary words, idioms and proverbs on web pages.
It helps non-native Japanese learners to discover new expressions while they are browsing the Internet.
Highlighting of rare words is useful because some people do not even notice vaguely known words, especially when these words are not critical for understanding of the text that they read. One possible explanation of this strange and pertexing effect is that mind of a reader is concentrated on understanding the meaning and structure of the text, and after finishing reading a sentence many readers won't go back to check the meaning of unfamiliar words that they have already forgot. E.g. some readers will forget to check the definition of word "pertexing" from the previous sentence which, in fact, doesn't exist. And even if you did check it, you still can try this extension, it highlights only real Japanese dictionary words and idioms =)

The source code is here if you are curious: https://github.com/cyj98/JapaneseHighlight

This extension if a fork of mechatroner's word-discoverer, which can be found here: https://chrome.google.com/webstore/detail/word-discoverer-expand-yo/noncaeikjgpbdeoocblijjgegnobogib.

You can also check my modified English version which use better frquency list and deinflector(can interpret dogs to dog etc.): https://github.com/cyj98/word-discoverer

Here are some features of the extension:

Depending on your vocabulary size, you can adjust frequency threshold of highlighted words e.g. skip 8000 most common Japanese words, and highlight all the rest. There's no way to set such threshold for idioms and proverbs, the extension can either highlight all of them or none.

Japanese Highlighter can operate in two modes:
In the first (default) mode it highlight all Internet pages except sites that you add to a special list. E.g. you may not want to highlight anything from youtube.
In the second mode Japanese Highlighter highlights only sites from another special list - your favorite Japanese sites. By default this list is empty, so unless you add there something (e.g. facebook, wikipedia), it won't highlight anything at all.

Currently there are 84364 words in the extension's dictionary. If you're interested you can look at them on project's github page.

If you known definition of a highlighted word, you can add it to your personal vocabulary and it won't be detected any more. You can always view your vocabulary or save it as a text file.

By selecting text of a word (or idiom) and right clicking on it you can either add the word to your vocabulary or view it's definition in one of 4 online dictionaries using context menu references. And, of course, you can also use Japanese Highlighter in combination with your favorite dictionary app (e.g. "Google dictionary" extension)You can also use custom dictionary.