About Prime Numbers List
Prime Numbers List writes out every prime number from two up to a value you choose. It is the table you want when a puzzle, a maths class or a bit of code needs the primes under some bound, produced instantly rather than worked out by hand.
Each candidate is tested the straightforward way - trial division against every smaller number up to its square root - and the survivors are collected into a comma-separated list under a header that states the count. Up to one hundred there are twenty-five primes, running from two through ninety-seven, and the default field is set to exactly that example.
Three edges shape how it behaves. The list always starts at two, so there is no lower bound and no interval other than the beginning of the numbers. A value below two - or a negative, or an empty field - produces the header 0 primes with an empty list rather than an error, and a decimal is floored before the run. The output is one long comma-joined line with no wrapping, which gets harder to scan the higher the bound climbs.
How to use Prime Numbers List
- 1 Enter the upper bound in the Up to N field.
- 2 Run the tool to read the count and the comma-separated list of primes.
- 3 Copy the list if you need it elsewhere, keeping in mind it is a single long line.
Frequently asked questions
How does it find the primes?
Every number from two up to the bound is tested by trial division against all smaller values up to its square root. Any number with no divisor other than one and itself is collected into the list.
Why does the list always start at two?
Two is the smallest prime and the run always begins there. There is no lower bound or interval setting, so the tool lists every prime from the start of the numbers up to the value you give.
Why did a value below two give an empty result?
There are no primes below two, so the tool reports 0 primes with an empty list rather than an error. A negative value or an empty field behaves the same way.
Why is the result one huge line?
The primes are joined by commas into a single line under the count header, with no wrapping or grouping into columns. For large bounds the line grows long, and there is no option to put one prime per line.
Free, online, and private
Free to use
Prime Numbers List is completely free. There is no account to create, no login, and no hidden charge or usage limit.
Runs online in your browser
It is a free online tool that runs entirely in your browser. Nothing to download or install — open the page and start using it right away.
Your data stays private
All processing happens locally on your device. Your input is never uploaded, stored, or tracked, so it never leaves your browser.
How Prime Numbers List behaves in detail
These are the specifics of this implementation — the exact ranges, defaults and fixed settings you are working with.
| Parameter | Value |
|---|---|
| Input | an Up to N number field starting at one hundred, with a form range from two to ten thousand |
| Output | a header line reading N primes: followed by every prime from two up to N inclusive, comma separated |
| Algorithm | each candidate is tested by trial division against all smaller divisors up to its square root |
| Default | up to one hundred yields 25 primes from two through ninety-seven |
| Edges | a value below two gives 0 primes with an empty list, and a decimal is floored to an integer first |
| Missing input | a missing value is read as zero by the run function, not as the field default of one hundred, so it reports an empty list |
Compiled from the implementation of this tool and checked against it by itoolnet.
What Prime Numbers List does not do
Knowing the edges of a tool saves more time than another list of its features. These are the cases where it will not do what you might expect.
- The output is one giant comma-joined line with no wrapping, grouping or pagination. At the top of the range the list runs to hundreds of primes on a single line, which is hard to scan or copy into a column - there is no option to put one prime per line.
- It only lists primes. There is no factorization, no primality test for a single number, no count-only mode and no interval with a lower bound other than two - the run always starts from the beginning of the numbers.
- The field cap is ten thousand, but the calculation reads whatever it is given: a negative value or a missing field produces an empty list with the header 0 primes rather than an error, and a decimal is floored silently.
Tested and documented by itoolnet, the team that builds and maintains this site.