CyberCodeRandom String Generator
Free online random string generator. Create cryptographically secure random strings with custom length and character sets (A-Z, a-z, 0-9, symbols) — ideal for tokens and API keys.
What makes a random string cryptographically secure?
Ordinary random functions like Math.random() are predictable — an observer who sees a few outputs can forecast the rest, which is fatal for tokens and keys. Cryptographically secure generators (CSPRNGs) draw from operating-system entropy and are unpredictable even to someone who knows the algorithm.
This tool uses crypto.getRandomValues with rejection sampling, which also removes modulo bias — every character in your chosen set is exactly equally likely. That is the correct way to mint API keys, session tokens and reset codes.
How to use
- 01Set the string length and how many strings to generate.
- 02Pick the character sets to include: A-Z, a-z, 0-9 and symbols.
- 03Click Generate — strings are created with cryptographically secure randomness.
- 04Copy the results for use as tokens, keys or test data.
Frequently asked questions
- Are these strings secure enough for tokens and keys?
- Yes. Characters are chosen using crypto.getRandomValues with rejection sampling to avoid bias — the same quality of randomness used by password managers.
- What length should an API token be?
- For 128-bit security with letters and digits, use at least 22 characters. 32+ characters is a comfortable standard for API keys.
- Are generated strings stored anywhere?
- No. Generation happens in your browser and results disappear when you leave the page.