RandomNr

Advanced and Statistical

Seeded Random Number Generator

Enter a seed and get the same sequence every time, which is what testing and shared demos need.

Seeded Random Number Generator

42

Seed random-nr, 1 to 100

Seed and range

The same seed always gives the same sequence

Options

How many numbers

Repeatable random numbers

A seeded generator turns a seed you choose into a fixed sequence of numbers. Enter the same seed and you get the same sequence every time, which is exactly what testing, debugging and shared demonstrations need. Change the seed and the sequence changes completely.

How seeding works

The seed text is hashed into a starting value, which drives a small deterministic generator. Because the maths is fixed, the same seed always retraces the same path, while a different seed sends it somewhere else entirely. The numbers still spread evenly across your range.

When to use it

Use a seed when a result must be reproducible: a test that should behave the same on every run, a demo two people need to see identically, or a shuffle you want to repeat. For an unpredictable draw instead, use an unseeded generator.

Popular generators

Frequently asked questions

What does the seed do

It fixes the sequence. The same seed always produces the same numbers, so a run is repeatable.

Is a seeded draw still random

It is pseudo random. The spread looks random, but it is fully determined by the seed, which is the point when you need to reproduce it.

When should I use a seed

For tests, debugging and shared demos where everyone should see the same result. For a truly unpredictable draw, use the standard generator.

Can I sort the output

Yes. Sorting orders the display without changing which numbers the seed produced.

Is it free

Yes, free and with no sign up.

Related generators

For an unpredictable draw use the random number generator, and to weight the odds see the weighted generator.