Random String Dataset Generator

Runs in browser Test Data

Thousands of strings at once — fixed or variable length, alphanumeric, with symbols, whitespace-only, empty, very long — exported as JSON, CSV or lines.

TEST DATA ONLY — all generated names, contacts, identifiers and numbers are synthetic and do not belong to real people or accounts.
Privacy: This tool runs entirely in your browser. Your input never leaves your device.

What is the difference between random and cryptographically secure random?

Ordinary random generators (Math.random) are fast and evenly distributed but predictable once a few outputs are known, which is fine for test data, sampling and shuffling. Secrets, tokens and session ids need a cryptographically secure generator (crypto.getRandomValues, /dev/urandom) whose output cannot be predicted even by someone who has seen earlier values.

How to use Random String Dataset Generator

  1. Set the length range and alphabet, or a pattern.
  2. Enable edge cases or uniqueness if needed.
  3. Press Generate and export.

Random String Dataset Generator features

  • Up to 1,000 strings with fixed or variable length (0–10,000 characters)
  • Alphabets: alphanumeric, letters, case-specific, digits, hex, symbols, printable ASCII, mixed Unicode scripts or custom characters
  • Mask patterns (AAA-999-aa) with escapes
  • Edge cases: empty, whitespace, padded, null/undefined words, NBSP, 255/256/10,000 characters
  • Unique-value mode and per-row length and byte counts
  • One-per-line, JSON, CSV, SQL, XML or JSON Lines output

Random String Dataset Generator example

Licence-key style strings

Input:

Pattern: AAAA-9999-AAAA · Strings: 3

Output:

DWPQ-2091-AHXK
NXKB-1763-QWER
XXYA-5900-AZMT

Frequently asked questions about Random String Dataset Generator

What alphabets are available?

Alphanumeric, letters, lower/upper case, digits, hex, symbols, all printable ASCII, a mixed-script Unicode pool or your own characters.

How do patterns work?

A mask such as AAA-999-aa where A is uppercase, a lowercase, 9 a digit, # alphanumeric, ? a symbol and * any ASCII character; use a backslash to keep a literal.

Which edge cases can be added?

Empty string, whitespace-only, leading/trailing spaces, the words null/undefined/true, non-breaking and ideographic spaces, and 255/256/10,000-character strings.

References