How the shuffle works
The deck is shuffled with the Fisher–Yates method. Starting from the last card, each position is swapped with a randomly chosen position at or before it. With unbiased random choices, this gives every possible ordering of the selected cards the same probability.
A tempting shortcut is to swap each card with any card in the deck, chosen from the full range each time. That does not produce all possible arrangements equally often: some orders can be reached in more ways than others. The difference is difficult to see in a single shuffle, but it becomes measurable across a large number of trials.
Where the randomness comes from
When your browser provides a cryptographic random number generator, the shuffler uses it to make the random choices required by Fisher–Yates. The random values are also sampled without introducing bias from an uneven range of possible values.
If a browser does not provide the cryptographic generator, the tool falls back to the browser’s ordinary random-number generator and lets you know. For an ordinary card game, that fallback is generally sufficient; cryptographic randomness is useful when you want stronger guarantees about the unpredictability of the shuffle.
For random values that aren't cards, use the Random Number Generator.
Your shuffle has probably never happened before
A 52-card deck has about 8 × 1067 possible orders. Even if people had been shuffling cards continuously for billions of years, the number of physical shuffles would still be tiny compared with the number of possible arrangements.
That makes it extraordinarily unlikely that a randomly shuffled deck will match a particular arrangement that has already occurred. A properly shuffled deck can therefore produce an order that has never been seen before.
If you’re interested in the chances of drawing particular cards or getting specific combinations, see our Die & Card Probability calculator.
How many riffle shuffles does a real deck need?
About seven. Mathematicians Dave Bayer and Persi Diaconis showed that roughly seven ordinary riffle shuffles are needed for a 52-card deck to become close to random under a standard mathematical model. Fewer shuffles can leave detectable traces of the original order.
A digital shuffle doesn't need repeated passes like a physical deck. One complete Fisher–Yates shuffle produces a uniformly random ordering when its random choices are unbiased.
Starting order
Before you shuffle, the cards are displayed in a fixed starting order: spades and hearts from ace to king, followed by diamonds and clubs from king to ace. This gives the tool a consistent order to return to when you press Reset order.
This is simply the starting arrangement used by the calculator; it is not intended to represent a universal factory order for every physical deck.
The number of possible card orders is a permutation question: arranging all 52 distinct cards gives 52! possible orders. You can explore related counting problems with our Permutation & Combination Calculator
Frequently asked questions
Is this shuffle really random?
It uses the Fisher–Yates algorithm with your browser's cryptographic random number generator, so every possible order is equally likely. If your browser doesn't offer that generator, the tool falls back to the ordinary one and says so underneath the cards.
How many ways can a deck of cards be arranged?
A standard 52-card deck can be arranged in 52! different orders, which is about 8.07 × 1067. If two jokers are included, a 54-card deck has 54! possible orders.
Can I use this for a real card game?
Yes. Shuffle, then deal from the top of the list. It works well over a video call, where one person can share the order or read cards out as they're dealt. Copy the order first if you'll need it after the page closes — nothing is saved.
What order are the cards in before shuffling?
Before shuffling, the tool uses a fixed starting order: spades and hearts run from ace to king, followed by diamonds and clubs from king to ace. The Reset order button returns the selected cards to this starting arrangement.
Can I shuffle a custom deck?
Yes. Open Customize Deck to choose the cards you want to include. You can use a standard 52-card deck, add either or both jokers, or select individual cards, ranks, or suits before shuffling.