Primel

About Primel

Primel is a small open-source game, published on GitHub by dill, that adapts Wordle to prime numbers. It has run since early 2022 and has inspired other number Wordles, such as Mathle, which credits it.

The answer is a five-digit prime, the same for everyone that day: the game picks it from a fixed list of over 8,000 primes using the number of days since 1 January 2022. You have six tries. Each guess has to be a valid five-digit prime, which is half the challenge. After each guess the tiles change colour: green means the digit is in the prime and in the right spot, yellow means it is in the prime but somewhere else, and grey means it is not in the prime.

There is a numeric keypad with Enter and Delete, and a Share button copies a coloured grid with the puzzle number.

It suits players who like number theory and want a daily puzzle where every guess also tests whether you can recognise a prime.

How to play Primel

1. Open Primel in a browser.
2. Type a five-digit prime number on the keypad and press Enter.
3. Read the colours: green is the right digit in the right place, yellow is in the prime elsewhere, grey is not in it.
4. Find the prime within six tries, then share your result.

Tips

• Primes above 5 never end in 0, 2, 4, 5, 6 or 8, so the last digit is 1, 3, 7 or 9.
• If a number's digit sum is divisible by 3, it is not prime; use this to check guesses quickly.
• Open with primes that use five different digits to test as many digits as possible.

Questions