---
id: pyopenjtalk
version: "0.4.1"
license: The pyopenjtalk package is licensed under the MIT "Expat" License: > Copyright (c) 2018: Ryuichi Yamamoto. > > Permission is hereby granted, free of charge, to any person obtaining > a copy of this… (full text in the JSON record)
license_treatment: permissive
maintenance: aging
---

# pyopenjtalk — A python wrapper for OpenJTalk

License: permissive · Maintenance: aging · Downloads: 83.1K/mo

## What it is and what it does

pyopenjtalk is a Python binding for OpenJTalk, a Japanese linguistic analysis and speech synthesis engine. It provides three main capabilities: text-to-speech synthesis that converts Japanese text to audio waveforms, grapheme-to-phoneme conversion that translates written Japanese to phonetic representations, and full-context label extraction for advanced linguistic processing. The package wraps modified versions of OpenJTalk and hts_engine_API to provide a unified interface for Japanese language processing tasks.

The package depends on numpy for numerical operations, tqdm for progress indication, and importlib_resources for resource management. It requires C/C++ compilation at install time, which means you must have a compiler toolchain, cmake, and cython available. The core use case is building Japanese speech synthesis systems, linguistic analysis pipelines, or text-to-speech applications that need accurate Japanese phonetic and prosodic processing.

Use it for:

- Build a Japanese text-to-speech system that converts written Japanese to natural-sounding speech audio.
- Extract phonetic representations and linguistic features from Japanese text for speech processing research.
- Create a Japanese pronunciation guide or phonetic transcription tool using grapheme-to-phoneme conversion.
- Develop a voice assistant or spoken dialogue system with Japanese language support.
- Process Japanese text with custom dictionaries for domain-specific pronunciation handling.

## Worth the install?

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

Wraps OpenJTalk to provide Japanese text-to-speech synthesis, grapheme-to-phoneme conversion, and linguistic text processing for Japanese.

Yes, with conditions. Install if you need Japanese TTS or linguistic processing and can meet the compilation requirements (C/C++ toolchain, cmake, cython). The MIT license is permissive. However, the package is aging (493 days since last release) and has high install friction due to compilation dependencies. Verify that pre-built wheels are available for your platform before committing to installation, as building from source can be time-consuming.

## Install

pip install pyopenjtalk
uv add pyopenjtalk
poetry add pyopenjtalk

## Installing pyopenjtalk

Before you install: High install friction: requires C/C++ compilers, cmake, and cython to build from source. The package has not been updated in 493 days and is marked as aging, though the repository remains active with recent commits.

License in practice: MIT license permits commercial and private use with minimal restrictions. The underlying OpenJTalk and htsvoice components carry different licenses (Modified BSD and others); review the bundled license files before deploying.

Quickstart:

pip install pyopenjtalk
import pyopenjtalk
x, sr = pyopenjtalk.tts("こんにちは")
pyopenjtalk.g2p("こんにちは")

Requires C/C++ compilers, cmake, and cython installed before pip install. Python >= 3.8 required.

Verify before relying:

- Whether pre-built wheels are available for all supported platforms or if compilation is always required.
- Current state of marine (DNN-based accent estimation) feature and whether it is actively maintained.
- Performance characteristics and latency for real-time TTS use cases.

## Package facts

- License: The pyopenjtalk package is licensed under the MIT "Expat" License: > Copyright (c) 2018: Ryuichi Yamamoto. > > Permission is hereby granted, free of charge, to any person obtaining > a copy of this… (full text in the JSON record) (permissive)
- Python support: supports_current
- Install friction: high
- Maintenance: aging
- Downloads: 83.1K/month (top 15,000 on PyPI)
- Known vulnerabilities: none known

## Tags

japanese text to speech, japanese tts synthesis, grapheme to phoneme japanese, openjtalk wrapper, japanese phoneme extraction, japanese linguistic processing, hts speech synthesis, japanese-nlp, speech-synthesis, phonetics

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