# Number primality tester

## World's simplest number tool

Quickly test if one or more numbers are prime numbers in your browser. To perform the check, just enter your numbers in the input field, select the primality test method in the options below, and this utility will display the status of your numbers. Created by developers for developers.

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Number primality tester tool
What is a number primality tester?

This is an online browser-based utility for running the primality check algorithm on one or more numbers. The tool tests if the given number has a divisor that is different from 1 and the number itself. If such a divisor exists, then your number is a composite, otherwise, your number is prime. The tool can check multiple numbers at once if they are listed as rows in the input. At the same time, you can define the test method – show a full analysis of all numbers, display only a list of primes, or get only composites. That's numberwang!

Number primality tester examples
Click to use

Primality Test for First Ten Odd Numbers

This example checks the first 10 odd numbers for primality, showing a full analysis for each number. As a result, you can see that there are 7 prime numbers and only 3 сomposites.

1
3
5
7
9
11
13
15
17
19

1 is not a prime
3 is a prime
5 is a prime
7 is a prime
9 is not a prime
11 is a prime
13 is a prime
15 is not a prime
17 is a prime
19 is a prime

**Required options**

Print the number followed by
whether it's a prime or not.

Filter Prime Numbers

In this example, we run the primality test algorithm for all numbers from 500 to 600. To simplify the results, we show only primes and ignore composite numbers.

500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600

503
509
521
523
541
547
557
563
569
571
577
587
593
599

**Required options**

Print only numbers that are prime.

Filter Composite Numbers

This example checks a list of 12 numbers of various lengths and filters all numbers that are not prime (that is, it returns all composites).

4413061
1231
839791
123456789
17
287500711
857663
987654321
311
13579
30762001
97531

123456789
987654321
13579
97531

**Required options**

Show only numbers that are сomposite.

Pro tips
Master online number tools

You can pass input to this tool via

__?input__query argument and it will automatically compute output. Here's how to type it in your browser's address bar. Click to try!
https://onlinenumbertools.com/number-primality-test

__?input__=1%0A3%0A5%0A7%0A9%0A11%0A13%0A15%0A17%0A19&test-all-numbers=true
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