Metasequoia IME for Windows

中文 README · Website · Docs · Privacy · Code signing policy

A free and open-source Chinese and Japanese input method for Windows 10 and 11, built on TSF with no legacy IMM32 path.

This repository is the whole Windows product: the TSF text service DLL, the resident server, the conversion engine, a self-written native GUI framework (all windows, including settings, are drawn with Direct2D) and the installer. The engine was imported from MSIME-Engine and specialized for Windows; it now lives in engine/ as a first-party component, so a plain clone builds the product. See engine/UPSTREAM.md.

This is a public beta. Expect rough edges and read the release notes before upgrading.

Install

Download the installer from Releases or the download page, run it, then switch with Win + Space.

Releases are code signed: up to v0.9.3 with the project's Certum Open Source Developer certificate, and from now on through SignPath in CI (see the code signing policy). An installer whose name ends in -unsigned was built without a signing certificate; SmartScreen will block it and uiAccess is unavailable, which means the candidate window cannot float above elevated applications. Either way, verify the download with the SHA256 published on the download page.

You need the Microsoft Visual C++ 2015–2022 Redistributable (x64). The server and settings app are 64-bit; the x86 redistributable is a separate package and does not substitute for it. If you cannot switch to the IME, the server keeps exiting, or the settings window closes immediately, install that first.

What it does

• Chinese input: full pinyin, double pinyin (Xiaohe / Ziranma / Shoudao / Microsoft / Sogou / Ziguang / Zhineng ABC / Guobiao / Pinyin Jiajia), Wubi 86
• Japanese input: romaji, with hiragana, katakana and dictionary candidates; also available as a temporary mode from Chinese
• Helpcode (形码) filtering on pinyin schemes: six tables, single- and double-code
• Optional cloud candidates, and AI suggestions via DeepSeek / OpenAI / SiliconFlow / Groq
• English-Chinese glosses in the vertical candidate window
• Mixed Chinese-English input, emoji and kaomoji, a dedicated English candidate mode
• Local input statistics (off by default): character counts and active time stay on this machine; view and clean them under Settings → Statistics
• Voice input with streaming recognition and optional cleanup
• Handwriting, on-screen keyboard, floating toolbar, clipboard history
• User dictionary management, candidate frequency tuning, skins with light and dark variants

Privacy

An input method sees every keystroke, so the boundaries are stated explicitly in PRIVACY.md: which features reach the network, what each one sends, what the defaults are, and how to turn each off.

Two things worth knowing up front. Cloud candidates are on by default — the composition spelling goes to Google's input-tools service, and it is the only network feature that works without you supplying a credential. API tokens are stored in plain text in config.toml, unlike macOS and Linux which use the Keychain and Secret Service.

There is no telemetry, analytics or crash reporting of any kind.

Building and contributing

CONTRIBUTING.md has the environment, the build order and what to run before opening a pull request. Contributions do not have to be code — dictionary entries, documentation, icons and compatibility testing all count, and the recruiting page lists them by area.

Note that most issues, documentation and code comments are in Chinese. English pull requests and issues are welcome.

Code signing policy

Free code signing provided by SignPath.io, certificate by SignPath Foundation.

What is signed, who the committers, reviewers and approvers are, the build and release process and the current status are in the code signing policy. The privacy policy is PRIVACY.md.

Licence

GPL-3.0. See LICENSE and THIRD_PARTY_NOTICES.txt.

Support the project

If Metasequoia IME helps you, feel free to buy me a roasted sweet potato, roasted corn, roasted chestnuts or roasted ginkgo nuts.