Kotobank (コトバンク)

Kotobank is a free web encyclopedia in Japanese that lets a search run across dictionaries, encyclopedias and databases supplied by publishers at the same time. It is operated by Business Architect Inc. and collects content with clear sourcing, with an emphasis on reliability of the entries it aggregates.

The site lists a keyword of the day, update notices for reference works such as the Britannica International Encyclopaedia (concise edition), the Chemistry Dictionary Second Edition, Nippon Encyclopedia (Nipponica) and Digital Daijisen Plus, a full list of dictionaries, and an access ranking page, alongside a paid plan that removes ads from the site.