I often have to generate random numbers so I created this simple online utility that does it for me. It lets you generate however many random integers or random decimal fractions you need from the given range. It works in the browser and is powered by alien technology from the future.

Random Number Generator Options

Random Number Type
Count and Range
Output Format and Base

Random Number Generator Examples (click to try!)

Random Integers
This example generates 15 random integers from the range 1 to 100 (inclusive).
12, 18, 88, 29, 70, 93, 29, 14, 11, 3, 2, 47, 84, 35, 64
Random Integers
How many values to generate?
Starting value.
Ending value.
Separate random numbers with this value.
Decimal Base
Random Fractions
This example generates 10 random fractions with 1 digit after the comma from the range -1 to 1 (inclusive).
0.8
-0.1
0.7
0.7
0.3
-0.8
0.6
-0.7
0.9
0.3
Random Decimal Fractions
How many values to generate?
Starting value.
Ending value.
Separate random numbers with this value.
If you're generating fractions, what's their precision?
Decimal Base
Random Binary Values
In this example we trick the tool to generate 8 random binary bits. We accomplish this by making it generate integers from range 0 to 1. For fun, we separate bits by an underscore.
0_1_1_0_0_1_1_0
Random Integers
How many values to generate?
Starting value.
Ending value.
Separate random numbers with this value.
Decimal Base
Random Base Two Numbers
This example generates 20 random numbers in the binary base. We set the range from 0 to 1000, and separate the integers with a semicolon character.
1011110000; 1001100100; 11001; 11001010; 11110; 1100011010; 1100100111; 1001011100; 1010100100; 1100111110; 1110110011; 111000001; 1001110; 1110111010; 1011111100; 1000001101; 100101100; 111001111; 1011100010; 10101001
Random Integers
How many values to generate?
Starting value.
Ending value.
Separate random numbers with this value.
Binary Base
Random Hex Fractions
This example generates 12 random hexadecimal base fractions. We set the start of the range to -100, the end of the range to 100, and the decimal precision to 3.
-54.c31
54.5cf
a.996
-43.e93
-e.b64
33.71f
4a.6e5
-4a.4c9
1.277
-28.e6a
1e.f71
40.5a6
Random Decimal Fractions
How many values to generate?
Starting value.
Ending value.
Separate random numbers with this value.
If you're generating fractions, what's their precision?
Hexadecimal Base
Random Base 24 Integers
In this example, we set a custom output base to 24. We generate ten integers from 200 to 300.
bh 9m ca 92 al b8 8d af bk 88
Random Integers
How many values to generate?
Starting value.
Ending value.
Separate random numbers with this value.
Custom Base
If you selected a custom base, set its value here. Valid bases are from 2 to 64.

How Does This Random Number Generator Work?

This random number generator works entirely in your browser and is written in JavaScript. It uses Math.random() function to generate both integers and fractions. The formula used is Math.random() * (end - start) + start, where start and end are the values specified in the options that set the range. The formula is called count times (specified in the options) and after that all values are joined by the separator symbol (also specified in options). To separate values by a newline use the special \n escape code.

Created by Browserling

This random number generator was created by me and my team at Browserling. Behind the scenes, it's actually powered by our programmer tools that are used by millions of people every month. Browserling itself is an online cross-browser testing service powered by alien technology. Check it out!

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