Primedle

What is Primedle?

Primedle is the daily prime number game. One four-digit prime is hidden each day, the same one for everybody, and you get 6 attempts to name it. The catch that makes Primedle its own puzzle rather than a number-guessing exercise is that every guess must itself be a four-digit prime. You cannot probe with 1234; you have to spend each attempt on a number that qualifies.

That constraint is doing real work. There are 9,000 four-digit numbers and only 1,061 of them are prime, so Primedle hands you a search space eight and a half times smaller than it looks — but only if you can recognise which numbers are in it. Primedle is equal parts deduction and recall, and the recall half improves faster than most players expect.

Primedle gives feedback on two independent channels after every guess. The first is direction: the answer is higher or lower than what you played. The second is per digit, Wordle-style — green for a digit in the right place, amber for a digit that is in the answer but somewhere else, grey for one that is not there at all. Neither channel gives the answer away alone. Together they close in fast.

How to play Primedle

1. Type any four-digit prime with the keypad or your keyboard and press Guess. Primedle rejects anything that is not prime without spending an attempt, so a wrong guess costs you nothing but time.
2. Read the tiles. Green means that digit is correct and in the correct position. Amber means the answer contains that digit elsewhere. Grey means the answer does not contain it.
3. Read the arrow beside the row. ↑ means the answer is a larger number than your guess, ↓ that it is smaller.
4. Combine the two. Direction narrows the range; the digit marks narrow which primes inside that range are still possible. That pairing is what Primedle is built around. Greyed digits are dimmed on the keypad so you do not have to keep track yourself.
5. Find it in as few guesses as you can. Primedle reveals the prime when the board ends, and a new one arrives at midnight UTC.

Nothing to install and no account needed to play Primedle. Primedle runs in the browser, keeps your board if you close the tab, and tracks your streak on its own.

A worked Primedle board

Here is a real three-guess solve, hunting 6791. Read O as green, ? as amber and . as grey:

Notice how little of that came from the arrow. Direction mattered once, to establish that the answer sat above the low thousands; everything after that was digit bookkeeping. On most Primedle boards the arrow matters early and the tiles matter late, which is the opposite of how new players use them.

Why Primedle only accepts primes

A version of Primedle that let you guess any four-digit number would be easier and far duller. You could binary-search the range in thirteen guesses with no thought at all, and the digit feedback would be decoration. Requiring every guess to be prime removes that option: you cannot always play the number in the middle of your range, because the number in the middle is usually not prime.

What Primedle gives you instead is a puzzle with a second skill in it. Knowing that 6791 is prime and 6793 is not is the kind of thing nobody sets out to learn and everybody picks up after a week of Primedle. The rules that do most of the work are small: no four-digit prime ends in 0, 2, 4, 5, 6 or 8, and none has a digit sum divisible by three. Those two facts alone rule out most of the numbers a Primedle player would otherwise waste an attempt typing.

Primedle scoring and the daily leaderboard

Solving sooner scores more. A first-guess Primedle solve is worth 6,000 EP and each further guess costs 800, so a six-guess Primedle board still banks 2,000. A Primedle board you do not solve scores on how many digits your best guess had in the right place, which means a near miss is worth more than a scattergun.

Every finished board joins the daily Primedle leaderboard, which resets with the prime at midnight UTC and breaks ties by who finished first. Playing Primedle also feeds the streak you carry across every game on the site.

Primedle strategy that actually works

Open wide, not in the middle

A good first Primedle guess uses four different digits spread across the range — something like 1289 or 3407. In Primedle you are not trying to be close with the opener; you are trying to test four digits at once. Opening with a prime full of repeated digits, or one clustered at the low end, wastes most of what the first attempt could have bought you.

Spend the second guess on new digits

The commonest Primedle mistake is chasing a single amber tile immediately. If your opener tested 1, 2, 8 and 9, your second should test four digits you have not tried yet. Two openers cover eight of the ten digits, and after that you usually know most of the answer's alphabet before you start worrying about order.

Let the last digit narrow the field

Every four-digit prime ends in 1, 3, 7 or 9. So a grey 1 and a grey 3 mean the answer ends in 7 or 9 — a fact worth more than most green tiles, and one the arrow will never tell you. Primedle players who track the final digit finish a Primedle board a guess sooner than those who do not.

Use the arrow to break ties, not to search

When two candidate primes both fit every tile on a Primedle board, the arrow decides between them for free. That is what direction is best for in Primedle: resolving the last ambiguity, rather than doing the searching itself.

Primedle and the other daily games here

Primedle is one of the daily games on dlegame.com. If you like the deduction, Hexdle asks a similar question about colour rather than primality, and Sequencedle asks you to find a rule rather than a number. All three reset at the same moment and share one streak.