Does iPhone Have a Random Number Generator? Yes, Sort Of

What is already on your iPhone

Calculator: turn the phone sideways (or open the scientific layout) and tap Rand. You get a decimal between 0 and 1, not a whole number. To turn it into 1 to 100 you multiply by 100, drop the decimals and add 1: a Rand of 0.4372 becomes 44. It works, but nobody does that maths at a party.

Shortcuts: the Random Number action takes a minimum and a maximum and returns a whole number. You build a shortcut once, then run it from the home screen or by name. It is good if you want the same range every time.

Siri: asking for a random number between two limits usually gets an answer, and so does flipping a coin or rolling a die. It is hands-free but needs you to speak, which is awkward in a classroom.

None of these remembers what it already drew, so none can promise "no repeats".

What to use instead, and why

Random fits on the first home screen because the number generator sits at the top of its Home tab, already filled in with Min 0 and Max 100. That default is 101 possible numbers, so each has a 0.99% chance, not 1%. Change the two fields, tap Generate, and a large whole number appears. Typing the limits backwards, 100 and 1, swaps them instead of showing an error.

The part the built-in tools cannot do is the no-repeat draw. In Bingo you type the top of the range next to Max numbers: (up to 9999), and each tap of Generate takes a number out of play for good. The board under the ball shows every number already drawn.

Why repeats matter: range 1 to 100
Method	Chance of any one number	Chance of at least one repeat in 10 draws
Calculator Rand, Shortcuts, Siri, or Random's number generator	1%	37.2%
Random's Bingo with Max numbers 100	1% on the first draw	0%

That 37.2% surprises people. Ten raffle tickets drawn from 1 to 100 with a plain generator have more than a one-in-three chance of a duplicate, and in a range of 1 to 6 four draws already repeat 72.2% of the time.

Is the iPhone's random number really random?

For daily use, yes. Random uses Swift's SystemRandomNumberGenerator, which on iOS takes its bits from the operating system's secure random source, the same kind used for encryption keys. There is no seed you can reset and no sequence to learn, and the app samples the range without the old "modulo" trick that slightly favours low numbers.

No testing lab has checked it, though. For a regulated lottery or gambling, a phone app is the wrong tool, whatever its source of randomness.

Where Random falls short

No history is a real limitation. At a class draw, getting a number like 37 and tapping Generate again out of habit means 37 is gone; nothing in the app brings it back. Record the screen if the result matters. Only Bingo keeps its drawn numbers, until Restart is tapped.

One number per tap; there is no "give me 5 numbers" field.
The keypad has no minus key, so negative ranges are awkward.
Bingo always starts at 1, so a no-repeat draw from 500 to 600 means drawing from 1 to 101 and adding 499 yourself.
No widget, no Shortcuts action and no Siri support of its own: you open the app.

No paywall here: ads keep running until you buy Remove Ads, and that purchase buys nothing else, just a quieter screen.

Questions and answers

Is there a random number generator on the iPhone calculator?

Yes, in the scientific layout: the Rand key gives a decimal between 0 and 1. Multiply by the size of your range, drop the decimals and add the bottom of the range: 0.4372 for 1 to 100 gives 44.

How do I get a random number with Apple Shortcuts?

In the Shortcuts app, make a new shortcut, add the Random Number action, set the minimum and maximum, and add a Show Result step. Run it from the home screen or by name. It does not remember earlier results.

Can Siri pick a random number?

Yes, ask for a random number between two values, for example 1 and 100. Each answer is independent, so the same number can come back.

Is a random number generator truly random?

Not in the physics sense, but the iOS secure random source cannot be predicted in practice, and Random draws from it with no seed. It is not certified, so do not use it for a lottery the law says must be drawn by an approved method.

Does the iPhone have a random number generator built in?