Just paste. Polished in 1 second.

Kaku is an AI writing utility that instantly handles text cleanup, reply generation, and Markdown conversion. No prompts needed. Paste it, and you're done.

Three modes to speed up every writing task

Text Cleanup

Fix typos, grammar mistakes, and improve readability. See exactly what changed with an inline diff view and a detailed list of corrections.

Reply Generation

Paste a received message and get three reply options instantly — Quick, Friendly, and Business tones. Pick your favorite and copy with one tap.

Markdown Conversion

Turn messy notes and meeting minutes into structured Markdown with proper headings, lists, and emphasis. Ready to paste into Notion, GitHub, or Qiita.

Built into every mode

Ultra-fast response (under 1 second)One-tap copyKeyboard shortcuts (⌘ + Enter)Auto language detection (EN/JA)Real-time streaming outputCharacter & word count

3 steps, 3 seconds. Done.

STEP 01

Paste

Copy your text and paste it into Kaku. Emails, Slack messages, meeting notes — anything works.

STEP 02

Generate

Hit the Generate button or press ⌘ + Enter. AI processes it in real time.

STEP 03

Copy & Use

Copy the result with one tap. Paste it straight into your email, Slack, or Notion.

Frequently Asked Questions

What is Kaku?

Kaku is an AI writing utility that cleans up text, generates replies, and converts to Markdown — just by pasting. No prompts needed.

Can I use it without logging in?

Yes. You can use Kaku up to 50 times per day without logging in.

Is my text stored?

No. Text is processed in memory only and discarded after completion. No text content is ever stored in a database.

Is my text used for AI training?

No. Our AI providers (Google Gemini API, OpenAI API) do not use API data for model training.

What are the three reply tones?

Quick (brief, to-the-point), Friendly (warm, casual), and Business (formal, polite). Free plan includes Quick only; Pro unlocks all three.

Is there a browser extension?

Currently available as a web app. Chrome and Safari extensions are planned for the future.

Make writing simpler.

No prompts needed. Just paste, and AI polishes it in 1 second.