Best for: Monolingual lookups for advanced learners
Free Japanese-language site that searches many dictionaries and encyclopedias at once, with clear sources. A monolingual dictionary for when you're ready to look words up in Japanese.
Android app for learning kanji, with stroke-order writing practice, flashcards, multiple-choice quizzes and spaced repetition, plus kanji and word search. The beginner kanji, radicals and kana are free with no ads; a one-time purchase unlocks the remaining kanji and custom study sets.
Free online Japanese-English dictionary. Search in English, kana, romaji or kanji, draw kanji by hand or by radical, and see example sentences and a JLPT tag on many words (taken from older unofficial lists, since the JLPT has not published official word lists since 2010).
Japanese-English dictionary app for Android that works fully offline, with example sentences, kanji details and the option to save words to lists.
