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Japanese Text Analyzer (日本語文章解析) is an AI-powered web app for breaking down Japanese sentences. You type or paste Japanese text, and it labels each word with its kana reading, romaji, and part of speech. A full translation appears below. Click any word to see its meaning in that sentence, its usage, its conjugation, and an example sentence.
Want to try it first? Open the live demo and start analyzing without deploying anything.
Analysis results with dictionary definition

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Features at a glance

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Read sentences

Sentence analysis

Label each word with furigana, romaji, and part of speech, and get a full translation automatically.

Word details

Click a word to see its meaning in the sentence, dictionary form, conjugation, and an example.

Multi-word selection

Get grammar patterns and set expressions explained as a whole. Merge a wrongly split word in one click.

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Work more smoothly

Sentence of the day and recent texts

The home page shows a new sentence each day, updated on Japan time. Your recent analyses are saved locally in your browser.

Image recognition

Upload or paste a screenshot to extract the Japanese text in it.

Read text aloud

Listen with Edge TTS or Gemini TTS, with adjustable speed and voice.

AI Japanese Assistant

Ask follow-up questions about grammar, vocabulary, and learning, in the context of the current sentence.

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Interface

  • Supports 简体中文, 繁體中文, English, and 한국어. The interface, translations, and definitions switch together.
  • Offers three themes: light, dark, and system. Works on desktop and mobile.
  • Splits long texts into chunks automatically. When you paste from a web page or Markdown, formatting and links are removed automatically.
Analysis interface in dark mode

Dark mode

AI Japanese Assistant on a phone

AI Japanese Assistant on a phone

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Models

The API key configured on the server is shared by all visitors. Users can also enter their own key in Settings. That key stays in their own browser, and the app server forwards it to the model provider with each request. For details, see Keys and privacy.

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Tech stack

  • Next.js 15 (App Router) and React 19
  • Tailwind CSS
  • DeepSeek and Gemini through OpenAI-compatible APIs
  • License: AGPL-3.0-only

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Next steps

Quickstart

Install dependencies locally and run the app in minutes.

Deployment

Deploy to Vercel, or run it on your own server with Docker.

Deploy with an AI agent

Hand deployment to an AI coding assistant such as Claude Code or Codex with a single sentence.

Configuration

Learn about every environment variable, the models, and the access password.