Random Playing Card
- 52
- Deck size
- 51
- Left in the deck
- 11
- Blackjack total
The dealer draws cards from a standard deck, 52 cards, or 54 with the jokers. The choice that matters is replacement: dealing without it is a real hand from a real deck, and dealing with it is 52 independent draws, which are very different things.
How it works
A deal without replacement shuffles the whole deck with Fisher-Yates and takes the first n cards, which is exactly what shuffling and dealing does physically. Each swap index comes from the browser cryptographic generator, so every one of the 52-factorial orderings is equally likely.
- Without replacement, a card cannot appear twice in one deal and the remaining count drops accordingly.
- With replacement, each card is drawn from a full deck every time, so the same card can come up repeatedly.
- The blackjack total counts aces as 11 and all face cards as 10, which is the conventional starting value.
- Jokers add two cards and have no blackjack value, so the total is not shown when one is dealt.
Fifty-two factorial is about 8 × 10^67. Any properly shuffled deck has almost certainly never existed before in that order, which is a genuinely startling fact about a very ordinary object.
Examples
A single card
Cards
1
Result
One card from 52, each with a 1.9% chance
The suit colour is shown as well as the symbol, and the full name is available to screen readers rather than only the symbol.
A five-card hand
Cards
5
No repeats
On
Result
Five distinct cards, 47 left in the deck
This is a real poker hand. With replacement turned on you could be dealt the ace of spades twice, which no physical deck can do.
Repeated draws
Cards
10
No repeats
Off
Result
Ten independent draws, repeats likely
Ten draws from 52 with replacement give roughly a 60% chance of at least one repeat, the birthday problem, on a smaller scale.
Frequently asked questions
What is the difference between the two repeat settings?
Without repeats, the deck is shuffled and cards are taken from the top, so a deal is a real hand, the same card cannot appear twice. With repeats, every card is drawn from a complete deck, so duplicates happen. Card games use the first; probability exercises often want the second.
Is the shuffle genuinely fair?
It uses Fisher-Yates with cryptographic randomness, which produces every possible ordering with equal probability. The classic naive shuffle, swapping each card with any other at random, does not, and biases certain orderings in a way that is invisible without measuring it.
How is the blackjack total calculated?
Aces count 11, face cards 10, and number cards their face value. Real blackjack drops an ace to 1 when the hand would otherwise bust, which depends on the rest of the hand. This shows the simple total rather than pretending to play the hand for you.
Does the remaining count persist between deals?
No. Each deal starts from a full shuffled deck, so the count shown is what would be left after that deal alone. It does not track a running shoe across multiple deals.
Can I get the same card twice in one deal?
Only with repeats turned on. With it off the deck is shuffled once and cards are taken in order, exactly as dealing works, so duplicates are impossible.