Korean Astrology

ChatGPT often gets
your Korean chart wrong.

Ask any AI for your saju (사주 / BaZi / Four Pillars) from just a birthday, and it miscalculates the most important pillar — a different answer every time. The reading was never the problem. The chart was.

Install on Google Play How it works

The chart, not the reading, was broken

  • A birthday alone isn't enough — the year, month, and hour pillars depend on precise solar-term astronomy, not a rough calendar guess
  • Ask again and you'll often get a different chart back
  • No AI can interpret a chart correctly if the chart itself is wrong

Saju Studio fixes exactly that — it calculates your Four Pillars on your device, then hands the verified chart to whichever AI you already use.

What's free, in full, forever

Accurate Four Pillars

Calculated from solar-term astronomy — the same method Korean saju has used for centuries — entirely on your device.

Your Ilju character

A zodiac animal in one of five element colors (like "Red Ox" or "White Dragon") — one of 60 collectible day-pillar identities. Share it with friends.

Copy an AI-ready prompt

One tap, two styles — Beginner (plain, MBTI-style) or Traditional (full myeongni depth). Paste into ChatGPT, Claude, Gemini, or any AI.

No sign-up, no ads

Your birth data never leaves your phone. Don't know your birth time? Your Day Pillar still works — add it later if you find it.

How it works

  1. Enter your birth date and time — solar calendar, any time zone.
  2. Meet your Ilju character — your day-pillar identity, one of 60.
  3. Copy the AI-ready prompt — paste it into whichever AI chat you already use for your reading.

Good fit / Not a good fit

Good fit

  • Curious about Korean saju (Four Pillars / BaZi), not just Western zodiac signs
  • Already use ChatGPT, Claude, Gemini, or another AI for reflection and self-understanding
  • Want to compare compatibility with a partner, crush, or friend — correctly calculated

Not a good fit

  • Looking for a daily horoscope notification feed
  • Want a definitive, fixed-fate prediction — saju is a map to read yourself, not a verdict
  • Need medical, legal, or financial advice — this app doesn't provide that

Frequently asked

Do I need a ChatGPT account to use this?

No. Your chart is calculated entirely on your device. The app copies an AI-ready prompt to your clipboard — paste it into ChatGPT, Claude, Gemini, or any AI chat you already use.

Is this the same as my Western zodiac sign?

No. Saju (Four Pillars / BaZi) is a Korean astrological system based on your exact birth year, month, day, and hour, calculated from solar-term astronomy — not the 12 Western zodiac signs.

Is my birth data sent to a server?

No. The chart is computed on your device. Nothing about your birth date or time is uploaded. See the privacy policy for details.

Is it free?

Your own chart is free, in full, forever — both reading styles, every focus area. Pro (one purchase, no subscription) unlocks your vault and compatibility with people you save.

Meet your Ilju character

Install Saju Studio on Google Play — free, no sign-up.

Install on Google Play