Random String Generator

About the Random String Generator

Set a length, choose how many strings you want and pick a character set: Alphanumeric (A–Z, a–z, 0–9), Letters Only, Numbers Only, Hexadecimal (0–9, a–f) or Custom. Press Generate Strings and the list appears, one string per line, ready to copy one at a time or all together.

Each character is chosen with crypto.getRandomValues, the browser's cryptographic random number generator, and values that would favour some characters are discarded, so every character in the set is equally likely. In Custom mode, repeated characters count once, so typing "aab" does not make "a" twice as likely. Under the character set buttons you can see how many distinct characters are in use and roughly how many bits of randomness each string carries (length × log2 of that number). A 32-character alphanumeric string carries about 191 bits.

The prefix and suffix are added unchanged to every string. They are handy for labelled values such as test_ user names or INV- reference codes, but they add no randomness.

Typical uses: test data for a form or database, coupon or invitation codes, temporary file names, or unique-looking IDs for a spreadsheet. For example, 50 eight-character codes from a custom set without look-alike characters (ABCDEFGHJKLMNPQRSTUVWXYZ23456789) make readable voucher codes. The list is not checked for repeats, so short strings drawn from a small set can repeat. For passwords with a strength meter, use the Password Generator; for UUIDs, use the Random Token Generator.