NUMBER LAB · EXPLORE WITH CONFIDENCE

Prime Number Range Explorer

List primes, composite numbers or twin prime pairs in an inclusive range, with exact sieve results and reusable exports.

Worked examplesBrowser processingTXT · CSV · JSON

Explore the example, or adjust the inputs. Save a project to keep your settings.

A useful starting point

From 1 through 20, the primes are 2, 3, 5, 7, 11, 13, 17 and 19.

Scope and limits

Endpoints from 0 to 2,000,000; interval span at most 100,000. This is an exact bounded sieve, not a large cryptographic prime generator.

Calculations run in your browser. Projects are saved only when you download them. Website advertising and analytics follow the privacy and consent settings. Import large integer CSV columns as text in spreadsheets to preserve their digits.

Using Prime Number Range Explorer

List primes, composite numbers or twin prime pairs in an inclusive range, with exact sieve results and reusable exports.

Choose a worked example or enter your own values in the labeled controls.
Adjust the available options. Results refresh when you leave a field or choose an option.
Review the result summary, interpretation and calculation table. Check any explicit limits or assumptions.
Copy the text or download TXT, CSV or JSON. Save a project to reopen the same inputs later.

Example

From 1 through 20, the primes are 2, 3, 5, 7, 11, 13, 17 and 19.

Questions & answers

Is 1 a prime or composite number?

Neither. Both lists exclude zero and one.

Are endpoints included in twin prime searches?

Yes. Both numbers of a twin pair must lie inside the selected inclusive interval.

Can I save and reopen my settings?

Yes. Save project downloads a JSON file for this tool. Open project restores it; undo and redo work during the current session.

Does the table contain every result?

The table is paginated in groups of 50. Downloads contain all listed rows. The partition tool intentionally caps its example listing while reporting the full exact count.