Hakkutsu — Japanese Immersion

AI-powered Japanese immersion browser extension. Learn Japanese while browsing the web.

Hakkutsu (発掘) is a fast, privacy-first Japanese immersion browser extension designed to help you read, understand, and mine Japanese vocabulary seamlessly as you browse the web. Whether you are reading articles, light novels, documentation, or manga, Hakkutsu provides instant inline dictionary lookups, pitch accent indicators, offline screen OCR, AI grammar breakdown, and 1-click Anki flashcard mining. Key Features: Smart Inline Dictionary and Parser - Instant morphological tokenization with Sudachi and Kuromoji. - Pitch accents, furigana readings, JLPT levels (N5 to N1), and Sino-Vietnamese (Hán-Việt) sounds. - Flexible lookup triggers: highlight text, double-click, or hold Alt while hovering. Offline Screenshot OCR - Crop any part of your screen (Ctrl + Shift + X) to scan and extract Japanese kanji and vertical text offline. - Powered by client-side Tesseract OCR running locally in a background worker. AI Grammar Breakdown - Connect your own Gemini or OpenAI API key for deep sentence structure analysis, idiom explanations, and contextual translations. AnkiConnect Sync and Built-in SRS - Export target words, readings, definitions, sentence context, and audio directly to your local Anki deck via AnkiConnect. - Built-in local Spaced Repetition System (SRS) dashboard for reviewing vocabulary anytime without external tools. Privacy First - All dictionary lookups, tokenizer data, and SRS cards remain strictly local on your device. Zero user tracking. Keyboard Shortcuts: - Ctrl + Shift + X: Crop and scan screen OCR - Alt + Hover: Quick hover word lookup - Esc: Close overlay or popup - Ctrl + Enter: Analyze text inside extension popup