Can I GuessYour Number?
Pick any 4-digit number — no repeated digits. The computer uses a smart filtering algorithm to deduce it, step by step.
How to Play
- 01
Pick your number
Think of any 4-digit number — each digit must be unique. For example: 5 2 8 1.
- 02
The computer opens
It starts with a randomly chosen first guess displayed on screen.
- 03
How many correct digits?
Count how many digits in the guess appear anywhere in your number (position doesn't matter).
- 04
How many correct positions?
Count how many digits are both the right digit AND in the exact right slot.
- 05
The pool narrows
Your feedback eliminates hundreds of candidates. The computer makes its next best guess.
- 06
Repeat until solved
Keep giving feedback. See how few rounds it takes for the algorithm to crack your number.
Smarter than it looks.
Not brute force — pure information theory applied to a number game.
Every valid combination, tracked.
The algorithm begins with all 4,536 valid 4-digit numbers (unique digits, non-zero start). After the first guess, this typically drops below 500.
Not random. Deductive.
By choosing guesses that maximally shrink the pool, the algorithm converges on your number in 4–6 rounds — nearly every time.
Fully client-side.
Zero network requests. Every filter, every guess, every update happens in your browser — instant, and works offline.
Think you can stump the computer?
Pick your secret 4-digit number. See how many rounds the algorithm needs.
Start Game
GuessIt