Random Number Generator for Any Range, Multiple and Unique Numbers
Generate one or many random numbers, choose custom ranges, prevent repeats, sort results, or use popular ranges such as 1 to 10, 1 to 100, and 1 to 1000.
Generate Random Numbers
Set the range and options, then generate a random number or a complete list.
Generate a Number, a List, or a Unique Set
Use the random number generator when you need one value, several values, or a no-repeat set inside a custom range. Enter the minimum and maximum, choose the quantity, then decide whether duplicates are allowed.
Integer mode is best for whole-number picks. Decimal mode is useful when you need test values or sample data with a chosen precision.
Example setup
Range: 1 to 100
Quantity: 5
Duplicates: Off
A possible result is 7, 22, 46, 71, 93.
What Makes a Random Pick Fair?
For a uniform integer draw, every available number should have the same chance of being selected. The size of the range determines that chance.
Possible integers = Maximum - Minimum + 1
A range from 1 to 10 contains 10 possible integers. Each number therefore has a 10% chance on one uniform draw. A range from 1 to 100 contains 100 possible integers, so each has a 1% chance.
The tool shows this probability for integer mode so the size of the range is easier to understand.
Why This Tool Uses Web Crypto
UtilityDocks creates the result locally in your browser with crypto.getRandomValues(). This browser API is designed to provide cryptographically strong random values.
That is different from using Math.random(), which is not intended for cryptographic-quality randomness.
Services based on physical measurements use a different method. RANDOM.ORG, for example, states that it derives randomness from atmospheric noise.
Why Simple Modulo Math Can Bias a Range
A common shortcut is to take a large random integer and apply a remainder operation to fit it into a smaller range. That can create uneven outcomes when the source range does not divide evenly by the requested range size.
This generator avoids that simple modulo-bias problem by rejecting source values that fall outside an evenly divisible region before mapping the accepted value into the final range.
The result is that each integer inside the chosen range remains equally eligible.
Random Numbers Without Repeats
Disable duplicates when every selected value must be unique. Once a number has been chosen, it is excluded from the rest of that generated set.
The number of requested values cannot exceed the number of available unique values.
Range 1 to 6
You can generate six unique integers at most.
Requesting seven unique results is impossible because the range contains only six values.
One Number vs Multiple Numbers
A single random number is useful for quick choices. Multiple-number mode is better for sampling, ordering, test data, and drawing several values at once.
UtilityDocks can create up to 1,000 values in one generation. You can keep the original generated order or sort the final list from low to high or high to low.
Sorting does not change which values were selected. It only changes how they are displayed after generation.
Integer and Decimal Generation
| Mode | Example input | Possible output | Typical use |
|---|---|---|---|
| Integer | 1 to 100 | 64 | Number picking, games, classroom tasks |
| Decimal | 0 to 10, 2 places | 7.38 | Testing, simulations, sample values |
Decimal precision matters when repeats are disabled. A range with two decimal places has a finite number of representable values at that chosen precision.
Popular Random Number Ranges
The main tool covers common number-picker ranges directly, so you do not need a separate generator for each range.
| Range | Possible integers | Chance of one specific number |
|---|---|---|
| 1 to 6 | 6 | 16.67% |
| 1 to 10 | 10 | 10% |
| 1 to 20 | 20 | 5% |
| 1 to 50 | 50 | 2% |
| 1 to 100 | 100 | 1% |
| 1 to 1000 | 1,000 | 0.1% |
These presets are shortcuts only. You can enter any supported custom minimum and maximum instead.
Using Negative Numbers
The generator also supports negative integer ranges. For example, a range from -50 to 50 includes negative values, zero, and positive values.
Possible integers = 50 - (-50) + 1 = 101
This can be useful for test data, simulations, coordinates, or any task where the range crosses zero.
When a Number Picker Is Useful
- Choosing a number for a classroom activity
- Creating sample values for software testing
- Generating a unique set from a known range
- Randomizing a simple order or sequence
- Producing values for simulations
- Making an unbiased numeric choice where each integer should have equal probability
For passwords or security credentials, use a dedicated Password Generator rather than treating a plain number picker as a password tool.
Limits and Cases Where Another Tool Is Better
This page is designed for general-purpose number generation. It is not a certified drawing system for regulated lotteries, official contests, or processes that require independent auditing.
It also does not create phone numbers, credit card numbers, account identifiers, or other structured records. Those are different tasks with different validation rules.
For development identifiers, use the UUID Generator. For placeholder copy, use the Lorem Ipsum Generator.
Questions About Random Number Generation
Can I generate numbers from 1 to 100?
Yes. Set the minimum to 1 and maximum to 100, or use the 1 to 100 preset.
Can I generate several numbers at once?
Yes. The tool supports up to 1,000 values in one generation.
Can I prevent repeated numbers?
Yes. Turn off Allow duplicates. The requested quantity must fit inside the number of unique values available.
Can I generate decimal values?
Yes. Choose Decimal mode and select between one and six decimal places.
Are the minimum and maximum included?
In integer mode, both endpoints are included in the possible range.
Does sorting make the results less random?
No. Sorting only changes the order shown after the values have already been generated.
Is this a true random number generator?
The tool uses cryptographically strong browser pseudorandomness through Web Crypto. It does not claim to measure a physical source of randomness.
Generation Method and Sources
Methodology reviewed September 15, 2026.
Integer generation uses browser Web Crypto and rejection sampling to avoid simple modulo bias. Results are produced locally in the browser.
- MDN Web Docs: Crypto.getRandomValues()
- W3C: Web Cryptography API
- NIST: Random Bit Generation and Entropy Guidance
- RANDOM.ORG: Randomness and Atmospheric Noise Documentation