Douji (同字)

Douji (同字) is an Anki add-on that instantly cross-references CJK characters across Japanese (Kanji), Simplified Chinese (Hanzi), and Traditional Chinese (Hanzi). Hover over any character in the reviewer while holding a modifier key to view its regional variant forms alongside Mandarin Pinyin and Japanese Kana readings in a clean, Yomitan-inspired popup.

<p align="center"> <img src="docs/assets/screenshot.png" alt="Douji Preview" width="560" /> </p>

Table of Contents

• How to Use
• Installation
• Configuration
• Compatibility
• Troubleshooting & FAQ
• Known Limitations
• Future Plans
• License

How to Use

Hold <kbd>Shift</kbd> (or your configured modifier key) and hover over any Hanzi or Kanji character on your cards. The tooltip will appear instantly with the cross-referenced forms and readings.

<p align="center"> <img src="docs/assets/demo.gif" alt="Hover Demo" width="560" /> </p>

• Regional Variants: Displays 🇯🇵 JP (Japanese), 🇨🇳 SC (Simplified Chinese), and 🇹🇼 TC (Traditional Chinese) forms.
• Readings: Displays tone-marked Pinyin (Mandarin) and On-yomi / Kun-yomi (Japanese Kana).
• Target Scope: Only CJK ideographs trigger lookups. Hovering over Kana (Hiragana/Katakana), Latin alphabet, numbers, or punctuation is automatically ignored with no popup.

Installation

Method 1: AnkiWeb (Recommended)

1. In Anki, go to Tools → Add-ons → Get Add-ons...
2. Paste the Add-on Code: 2058654519
3. Click OK and restart Anki.

Ankiweb page: https://ankiweb.net/shared/info/2058654519

Method 2: Manual (.ankiaddon)

1. Download the latest .ankiaddon file from the Releases page.
2. Double-click the downloaded file or drag and drop it into Anki.
3. Restart Anki.

Configuration

Customize behavior, keys, fonts, and appearance via Tools → Add-ons → select this add-on → Config.

Note: "None" triggers on every hover without any key pressed, which may cause popup spam while reading.

For detailed explanations of all settings, see config.md.

Compatibility

• Tested Version: Anki 25.09+ (Qt6 / Python 3.13 / Chromium 122)
• Operating Systems: Windows, macOS, Linux
• Platform: Desktop Anki only (AnkiMobile for iOS, AnkiDroid for Android, and AnkiWeb are unsupported because Python add-ons run strictly in desktop Qt environments)

Troubleshooting & FAQ

The popup doesn't appear when hovering over text

• Ensure you are holding down the configured modifier_key (default: <kbd>Shift</kbd>).
• Verify that your card template CSS does not have user-select: none; or pointer-events: none; on the text container, which prevents browser caret hit-testing.
• Confirm the character is a Hanzi/Kanji ideograph (Kana, Latin characters, and punctuation do not trigger popups).

The popup appears underneath card elements or other add-ons

• Check if your card styling or third-party add-ons set excessive z-index values on parent containers that trap the tooltip layer.

A character shows "No cross-reference found"

• The character is likely an unmapped rare variant or outside the 9,688 character cluster dataset.

Known Limitations

• Cross-referencing operates on individual CJK ideographs rather than multi-character compound words.
• Requires the desktop Qt webview reviewer.
• Only shows characters with equivalence in all three variants. This means it can't be used to check Simplified-Traditional Mandarin only.
• Definitions are unified using the Unihan database and provide a generalized English meaning. They do not differentiate between distinct Chinese and Japanese usages of the same character.
• Definitions might not show the most useful or relevant meanings in some cases, as they are automatically generated from the Unihan database.

Future Plans

• Persistent popup, closer to Yomitan, which will allow for popup elements to be clickable
• Primitive decomposition for characters

License

This project is licensed under the GNU General Public License v3.0.