deinja is a lightweight JavaScript library that converts inflected Japanese words into their original forms.
Instead of aiming for perfect accuracy, deinja prioritizes speed and simplicity. It does not include internal dictionary data, which means it may return multiple possible candidates for each input rather than a single definitive answer.
This library was originally a component of Mouse Dictionary, and has since been extracted into a standalone module.
npm i deinja
import deinja from "deinja";
deinja.convert("素早く"); // ["素早い"]
deinja.convert("転がし"); // ["転がす"]
deinja.convert("投げた"); // ["投げる", "投ぐ"]
deinja.convert("死にました"); // ["死ぬ"]
deinja.convert("終わって"); // ["終わう", "終わつ", "終わる"]
deinja.convert("しまった"); // ["しまう", "しまつ", "しまる"]Apache 2.0
deinja is built upon deinflector, a Java-based tool for Japanese word normalization.