Random Number Generator



Minimum possible value
Maximum possible value
Generate this many numbers


Include up to this many decimal places


Pseudo (faster)
Cryptographic (slower, more secure)

Separate multiple numbers with:

Space (1 2)
Comma and space (1, 2)
Comma and no space (1,2)
New line for each
No separator (12)

Unique Numbers

Only allow unique numbers (No duplicates)

Sort numbers:

Low to high
High to low


Random Number:

Free online random number generator

This customizable random number generator lets you generate multiple, decimal, cryptographic, negative and huge random numbers. You can also sort the random numbers from high to low, low to high, and choose whether only unique numbers are produced (no duplicates). Features explained:

Customizable random number generator features

This random number generator can accurately and quickly produce huge random numbers including up to 100 negative digits, and positive 100 digits. That's -10^10 to 10^10. It should be a big enough range for pretty much anything imaginable. Generate random numbers with a ridiculously low lower limit, and ridiculously high upper limit. Choose the minimum and maximum values that you need. You can also generate single or multiple random numbers - as few as 1 to as as many as 50,000 in one click. You can generate multiple random negative and positive numbers.

Another powerful feature of this random number generator is the ability to include up to 53 decimal places in the random numbers that are produced. Simply select from the drop down how many decimal points you want included, 0 is the default. You can produce random numbers between -0.5 and 1.5 for example.

You can customize this random number generator to display the results in a variety of ways. You can choose to have the numbers displayed with a certain divider/separator, including with spaces, commas, spaces and commas, or put every result on a new line, or no spaces at all.

Another very useful feature is the ability to produce only unique random numbers in the results. This means there would be no duplicates. If a number has already been picked randomly, it will not be picked and displayed again. This can be useful if you want to randomly pick the order of a set number of things - such as the order your students present. It can also be useful to make sure that only one prize is given out per person when picking names in a raffle, for example.

This random number generator can also be set to sort the random numbers from highest to lowest (descending) or lowest to highest(ascending), or not at all. Sorting the numbers generated can be very useful for when you go to make use of the numbers that are created.

Cryptographic Random Numbers

This random number generator gives you the option to produce numbers using a cryptographically strong random number generation library - OpenSSL's openssl_random_pseudo_bytes. This means the numbers produced are based on the same engine and algorithms that produce random numbers for cryptographic purposes (encryption, decryption). Cryptography is important for financial institutions, order processing, online security, government, etc. One potential drawback is the number generation may be slower when generating large quantities of numbers compared to the simpler pseudo random option, which makes use of PHP's mt_rand() feature. Pseudo random number generation engines, on the other hand, generate random numbers based off of algorithms that are technically random, and meet the definition of random, but use definitive algorithms. These would not be ideal for cryptographic purposes. For most casual purposes, however, pseudo random numbers are secure enough. And nonetheless, random numbers sent over standard HTTP protocols shouldn't be used for security purposes anyways, but rather HTTPS should be used. For more information on cryptography, see http://www.garykessler.net/library/crypto.html

What about true randomness you may ask? Well true random numbers are themselves theoretical in nature. All random numbers generated by computers require a certain "seed" value that is put into a complex algorithm that randomizes that value. The more random the seed value the better. However, even the universe has uniformity. Radiation and atoms may seem random in nature, but then why does the earth hold together? Or our bodies don't explode? Believers of true random numbers are therefore proponents of the fallible Chaos Theory. Or something like that.

Simulate Anything

Ultimately random numbers can be very useful for a huge variety of purposes, whether it's educational, entertainment, financial, raffle draws, lottery picks, etc. The need for a random number generator that can be customized to your many needs is important.

If you want to use the random number generator to simulate many throws of a dice for example, you can do it just by setting the numbers to between 1 and 6. Or maybe you want to simulate a lottery pick - just generate 7 random numbers between 1 and 49 for example.