Mozc - a Japanese Input Method Editor designed for multi-platform

Copyright 2010-2026 Google LLC

Mozc is a Japanese Input Method Editor (IME) designed for multi-platform such as Android OS, Apple macOS, Chromium OS, GNU/Linux and Microsoft Windows. This OpenSource project originates from Google Japanese Input.

Mozc is not an officially supported Google product.

Build Status

| Linux | Windows | macOS | Android lib | |:-----:|:-------:|:-----:|:-----------:| | | | | |

What's Mozc?

For historical reasons, the project name Mozc has two different meanings:

1. Internal code name of Google Japanese Input that is still commonly used inside Google.
2. Project name to release a subset of Google Japanese Input in the form of source code under OSS license without any warranty nor user support.

In this repository, Mozc means the second definition unless otherwise noted.

Detailed differences between Google Japanese Input and Mozc are described in About Branding.

Build Instructions

• How to build Mozc for Android: for Android library (libmozc.so)
• How to build Mozc for Linux: for Linux desktop
• How to build Mozc for macOS: for macOS build
• How to build Mozc for Windows: for Windows

Release Plan

tl;dr. There is no stable version.

As described in About Branding page, Google does not promise any official QA for OSS Mozc project. Because of this, Mozc does not have a concept of Stable Release. Instead we change version number every time when we introduce non-trivial change. If you are interested in packaging Mozc source code, or developing your own products based on Mozc, feel free to pick up any version. They should be equally stable (or equally unstable) in terms of no official QA process.

Release History page may have additional information and useful links about recent changes.

License

All Mozc code written by Google is released under The BSD 3-Clause License. For third party code under src/third_party directory, see each sub directory to find the copyright notice. Note also that outside src/third_party following directories contain third party code.

src/data/dictionary_oss/

Mixed. See src/data/dictionary_oss/README.txt

src/data/test/dictionary/

The same as src/data/dictionary_oss/. See src/data/dictionary_oss/README.txt

src/data/test/stress_test/

Public Domain. See the comment in src/data/test/stress_test/sentences.txt