Frequently Asked Questions

This page tries to answer some common question about the Random Code Generator and Code Validator.

Random Code Generator

Code Validator


Random Code Generator

Why is the result set smaller than the amount I requested?

The amount of possible unique codes is determined by the selected length and charactersets or by the selected pattern.
It is impossible to generate more unique codes than this amount.

By unchecking the "Remove look-a-likes" box you will probably get a somewhat larger result set. If this still is not enough, increase the length, selected charactersets or pattern to allow a larger amount of possible unique codes.

Why are large result sets always saved as a CSV file?

Most browsers have problems displaying large amounts of text, which might cause them to become unresponsive.
To avoid this, large result sets (more than 1.000 results) are offered as a downloadable Comma Seperated Values (CSV) file, which can be openend in most plain-text editors as well as in Microsoft Excel or similar programs.

Should I use "Generate using characterset" or a "Generate using pattern"?

If you need codes of a specific length containing characters of a different types (uppercase, lowercase, digits, ...) you should "Generate using characterset". Codes like this are typically used for passwords and sweepstakes.
If you need codes that have a specific pattern (ie. XXX-9999-XX) you should "Generate using pattern". Codes like this are typically used for serial numbers and promotional codes.

A pattern can be defined by using the following characters:

  • X = Uppercase (A, B, C, ...)
  • x = Lowercase (a, b, c, ...)
  • 9 = Digits (0, 1, 2, ...)
  • # = Special characters ($, %, &, ...)
  • ! = Punctuation (!, ?, ...)
  • [ = Brackets ([, ], <, ...)
  • a = Vowels (a, e, i, ...)
  • b = Consonants (b, c, d, ...)
  • / = Escape character

Should I read the result set per row or per column?

The codes are displayed on screen per row, not per column. If you want to read them in the order they were generated, you should read them per row. Since the generated code are random, this probably doesn't matter much.

What is the maximum amount of codes I can generate?

The maximum amount of codes that can be generated in one result set is 100.000, which should be enough for most purposes. If you need more codes, you can run the tool again. Please note that the codes in each result set are unique, but duplicates can occur when multiple result sets are combined!

What is the maximum length for a generated code?

The maximum length for a single code is 100 positions.

How do I create pronouncable codes?

To create pronouncable codes use the "Generate using pattern" option. Pronouncable codes are defined by a pattern where vowels (a, e, i, ...) and consonants (b, c, d, ...) are used in an alternating fashion. Do not use more than two vowels or consonants repeatedly.

Some example of patterns that create pronouncable codes are:

  • abababab = Vowel / Consonant / Vowel / Consonant / Vowel / Consonant / Vowel
  • babbaab = Consonant / Vowel / Consonant / Consonant / Vowel / Vowel / Consonant
  • aabaabba = Vowel / Vowel / Consonant / Vowel / Vowel / Consonant / Consonant / Vowel
  • baabaab = Consonant / Vowel / Vowel / Consonant / Vowel / Vowel / Consonant

Please note that probably not all generated codes can be pronounced, due to an unusual combination of characters. Also note that only lowercase characters are used to make the codes more readable.

How random are the codes?

Pretty random.
Unfortunately, it is theoretically impossible to prove that the generated codes are really random. However, there is a little test devised by Bo Allen which creates a visual representation of the randomness. Because the human eye is very good at spotting patterns, this gives an impression of the randomness of the generator - the more random the image looks, the better the generator works.

True Randomness
True random (Random.org) 		True Randomness
Pseudo random (PHP rand() ) 		True Randomness
This generator

The Pseudo Random Number Generator which is used by the PHP rand() function shows some clearly defined patterns, which are essentially predictable results. The randomness created by this generator matches the randomness generated by the True Random Number Generator from Random.org.

The image for this generator is calculated on each page load.

Which algorithm is used to create the random codes?

This tool uses the Mersenne Twister algorithm, which is a very fast (pseudo)random number generator.

Can I use this tool for cryptography?

You shouldn't. For more information, have a look at the Wikipedia article about the Cryptographically secure pseudorandom number generator.

Do you store the generated codes?

No. Each character for each code is generated at random at the time it is requested. We don't have a list of pre-generated codes from which the results are choosen, nor do we store the codes after they have been generated.

It is not possible for us to recreate a specific result set, not even if you want us to.


Code Validator

How is the password strength calculated?

There is no official system to measure the strength of a password. Please note that this tool does not utilize the typical "days-to-crack" approach for strength determination.

The strength of a password is based on the length of the code and the number of different characters and charactersets used in the code. Bonus points are given for variation and points are deducted for repetitive characters. This tool is specifically designed to reward unpredictable codes.

The result is a percentage for each code, where 0% indicates a very weak code and 100% indicates a very strong code.

The result is a percentage for each code.
0% - 20% = Very weak
20% - 40% = Weak
40% - 60% = Good
60% - 80% = Strong
80% - 100% = Very strong

The used formulas are a direct implementation of the formulas developed by www.passwordmeter.com.

Why are large result sets always saved as a CSV file?

Most browsers have problems displaying large amounts of text, which might cause them to become unresponsive.
To avoid this, large result sets (more than 1.000 results) are offered as a downloadable Comma Seperated Values (CSV) file, which can be openend in most plain-text editors as well as in Microsoft Excel or similar programs.

What is the maximum amount of codes I can validate?

The maximum amount of codes that can be validated in one result set is 10.000, which should be enough for most purposes. If you need to validate more codes, you can run the tool again.

What is the maximum length for a code to validate?

The maximum length for a single code is 100 positions.

Can I use this tool to create fake creditcard numbers?

No. This tool uses the same algorithm that the creditcard companies use to validate if a number is valid. This does not mean that a valid number is actually in use on a creditcard, nor does this enable anyone to use this number for (online) payments.

My country is not listed, how can I check my postal code / phone number?

Only the countries are listed for which we know both the postal code format and phone number format. If you want your country listed, please contact us and tell us how the postal codes and phone numbers look in your country, and we will add it as soon as possible!

There is an error in your validation!

If you find any errors in the validation, please contact us and tell us what validation you were trying to perform, and which codes gave the wrong result. We will fix the error as soon as possible.