---
id: unidic
version: "1.1.0"
license: MIT
license_treatment: permissive
maintenance: aging
---

# unidic — UniDic packaged for Python

License: permissive · Maintenance: aging · Downloads: 416.4K/mo

## What it is and what it does

unidic-py packages the UniDic 2.3.0 Japanese morphological dictionary for pip installation. UniDic is a comprehensive lexical resource maintained by NINJAL (the National Institute for Japanese Language and Linguistics) that includes detailed linguistic annotations for Japanese words: part-of-speech tags, conjugation types, lemmas, pronunciations, etymological categories, and accent information. The package itself is a thin wrapper; after installation, you must run `python -m unidic download` to fetch the dictionary data from AWS, which takes up approximately 1GB of disk space.

Once installed, unidic exposes the DICDIR constant to locate the dictionary. The package includes minor modifications from the official UniDic release (additions for 令和, removal of single-character numeric/alphabetic entries, and changes to unknown-punctuation handling) to improve usability in Python workflows. It is designed to work with MeCab-based tokenizers that can accept a dictionary path argument.

Use it for:

- Japanese NLP pipelines that need detailed morphological analysis beyond basic part-of-speech tags, such as lemmatization or conjugation-type identification.
- Building Japanese text processing systems that require the full UniDic annotation set for linguistic research or production NLP.
- Japanese language learning or corpus analysis tools that benefit from rich lemma and pronunciation data.
- Accent analysis and standard-language pronunciation research using the aType and kana fields in UniDic.
- Counting-expression parsing in Japanese text, using the specialized iConType and fConType fields for numeric and counter contexts.

## Worth the install?

AI-flagged interpretation of the facts above — verify before relying.

Provides the UniDic 2.3.0 Japanese morphological dictionary for use with MeCab-based tokenizers, requiring a separate download step and consuming approximately 1GB of disk space.

Yes, if you need full Japanese morphological analysis and are willing to accept the 1GB disk footprint and the two-step installation process (pip install + manual download). The dictionary is comprehensive and well-maintained by NINJAL. No, if you want a lightweight solution—the package explicitly recommends unidic-lite as an alternative. The aging maintenance status (last release 2021-10-10) is a minor concern but not a blocker, since the dictionary data is stable and the code is minimal.

## Install

pip install unidic
uv add unidic
poetry add unidic

## Installing unidic

Before you install: Installation has high friction: the package itself is small, but the dictionary data must be downloaded separately via `python -m unidic download` after pip install, and the full dictionary occupies approximately 1GB on disk. The project is aging (last release 2021-10-10, 1769 days ago), though the repository remains active with recent commits.

License in practice: MIT license on the code is permissive and poses no restrictions. The UniDic dictionary data itself is available under GPL, LGPL, or BSD (user's choice per the UniDic Consortium); the package distributes it under BSD terms. No licensing barrier to use.

Quickstart:

pip install unidic
python -m unidic download

import unidic
dicdir = unidic.DICDIR

Requires a MeCab installation and a MeCab-based tokenizer library as a separate runtime dependency to actually tokenize text; unidic alone provides only the dictionary data and the DICDIR path.

Verify before relying:

- Whether the 1GB disk requirement is accurate for the current 2.3.0 dictionary version or has changed.
- Current state of the AWS Open Data mirror hosting the dictionary—whether downloads remain reliable.
- Whether the package works with Python versions newer than 3.5 without issues, given the aging maintenance status.
- Actual integration behavior with MeCab-based tokenizers when installed alongside them.

## Package facts

- License: MIT (permissive)
- Python support: supports_current
- Install friction: high
- Maintenance: aging
- Downloads: 416.4K/month (top 15,000 on PyPI)
- Known vulnerabilities: none known

## Tags

japanese morphological dictionary, unidic mecab tokenizer, japanese pos tagging, japanese nlp dictionary, japanese lemmatization, mecab dictionary japanese, japanese linguistic analysis, japanese-nlp, morphological-analysis, mecab-dictionary

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