How Does Online Poker Deal Cards

Online poker sites use random number generator algorithms to fairly shuffle and deal cards to online poker players. Learn how it works!

how do online poker sites deal cards fairly
How Does Online Poker Deal Cards

Without a physical deck of cards that can be seen to be shuffled by the players at the table, online poker sites have to find a fair way to shuffle and deal virtual cards. But how exactly does it work and how do we know that it's as fair, if not fairer than a regular poker card shuffle?

How Online Poker Shuffle the Cards

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Legitimate online casino rooms use computerized algorithms to fairly shuffle and distribute cards.

  1. Each suited card in the deck is assigned a unique identifier (e.g., a number between 1 and 208)
  2. Before the start of each hand, the deck is 'created' by using a random number generator, randomly ordering these numbers.
  3. Once the deck has been built, the hand is then dealt as it would be in a live game with each player being given two cards, starting with the small blind.

Technically speaking, there are two ways an online poker site can generate the numbers to order their deck, either by using a PRNG or a TRNG.


PRNG stands for pseudo-random Number generator and is so-called as the randomness is simulated through an algorithm rather than naturally generated. The numbers a PRNG generates can never be called truly random as they're determined by an initial value, called a 'seed'.

PRNGs are often extremely complicated algorithms and nigh on impossible to reverse engineer without a large amount of information on how the specific algorithm works. That coupled with the benefit of speed when generating numbers makes them very useful for online poker.

However, not all PRNGs are created equal and some are a lot better than others. If a site you play on uses a PRNG it's important that you check out their credentials to make sure their PRNG has been verified.

For example, Party Poker uses a PRNG and uses an external lab to audit the fairness of the PRNG every month and posts their findings on their website.


TRNG stands for true random number generator and is so-called as the numbers it generates are completely random. There is no algorithm used to generate the numbers, instead, they use naturally random methods to determine a numerical sequence.

Pokerstars is the most prominent online poker site to use a TRNG and they use two methods combined to come up with their random numbers. The first method they use to generate random numbers is to shoot a ray of light at a piece of translucent glass; if the light is reflected it is a 1, if it is not it is a 0.

Secondly, they track the mouse movements and clicks of each player to generate a second stream of 1s and 0s. All of that is then connected and cryptographed to generate a completely random stream of 1s and 0s from which the numbers 1 to 52 are extracted to make a completely random deck.

The randomness of poker is similar to the randomness of slot games.

Online Poker Software Security

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The only way to verify if a site's PRNG is truly random, or if a site that uses a TRNG isn't 'rigging the system' is to have them audited by an outside company. We as players don't have enough information to be able to verify sites ourselves so we rely on poker site operators and gaming regulators to independently verify the legitimacy of online poker sites.

Many trusted poker sites will do this of their own accord as they know that be open and transparent with their players about the legitimacy of their operations is a good way to keep players on their site. For example, we've already mentioned that Party Poker has an independent company audit their PRNG every month, and PokerStars regularly sends detailed data on their RNG to Cigital for them to verify that their game is truly random.

After the Ultimate Bet scandal where one of the site owners used a back door in the software to view people's hole cards, online poker sites are now very careful about who in their company gets access to the backend of the system and anyone who does have access is banned from playing on that site in the interest of fairness. 

Play with a Legit Online Poker Software

If you're planning to play on a new site but are unsure about whether or not it's fully above-board, what should you do? My advice would be to look out for the following things, if they tick all these boxes they're likely a legitimate site.


Having their random number generator certified by a trusted third-party cybersecurity company is a great indicator that their site is legitimate. It shows that they have nothing to hide in the way they run the most important part of the site and you'll know that you will get a fair game.

Active Customer Support

An active customer support shows that they care about their customers and are willing to help solve any issues you might encounter whilst playing on their site. If a company doesn't offer this then at best they don't care about their customers and at worst they're trying to hide something from their customers.

Positive Reviews

Knowing the opinions of other players who have played on a site can be a great way to know if the site is worth playing on. If other players have had good experiences and are willing to share, you will likely have one too. However, if a lot of players have bad experiences on the site, it's also likely that you'll have a bad experience as well.


In the majority of countries around the world, an online poker site must have a license in order to operate and offer real money games. If a site is licensed it means they must comply with the rules from the gambling regulators in the jurisdiction and will face penalties if they don't. If a site is not licensed, they are not regulated by these rules and there is no punishment for running a dishonest game.

Despite what some people at your local home game might think, online poker sites are fair in the way they use random number generators to shuffle and deal cards.

This article was published on September 17, 2021, and last updated on October 26, 2022.