What Is a Random String Generator?
A random string generator creates sequences of characters chosen randomly from a defined character set. Unlike passwords, random strings are used in a wide variety of programming contexts — from generating unique identifiers to creating test data.
Our generator uses cryptographically secure randomness (System.Security.Cryptography.RandomNumberGenerator), ensuring that generated strings are unpredictable and suitable for security-sensitive applications.
Common Uses for Random Strings
- API keys and tokens — Generate unique strings for authentication tokens, API keys, and session identifiers.
- Database IDs — Create unique identifiers when sequential IDs are not desirable (e.g., public-facing URLs).
- Test data — Generate random input for unit tests, load tests, and data seeding scripts.
- File names — Create unique temporary file or upload names to avoid collisions.
- Verification codes — Generate short alphanumeric codes for email verification, two-factor authentication, or coupon codes.
- Salt values — Create random salt strings for password hashing and cryptographic operations.
Tip: For maximum randomness and security, enable all character types (uppercase, lowercase, digits, symbols). The larger the character pool, the more entropy each character provides.
String Length and Entropy
The entropy of a random string depends on both its length and the size of the character pool. Entropy is measured in bits and calculated as: length × log2(pool_size).
- Lowercase only (26 chars) — ~4.7 bits per character. A 32-char string has ~150 bits of entropy.
- Alphanumeric (62 chars) — ~5.95 bits per character. A 32-char string has ~190 bits of entropy.
- All characters (76 chars) — ~6.25 bits per character. A 32-char string has ~200 bits of entropy.
Frequently Asked Questions
Is this generator truly random?
Yes. We use cryptographically secure pseudo-random number generation (CSPRNG) provided by the .NET runtime. This means the output is unpredictable and suitable for security-critical applications like token generation.
What is the difference between a random string and a password?
Technically, they are similar. However, passwords are specifically intended for authentication and may have additional requirements (like avoiding ambiguous characters). Random strings are more general-purpose and used for identifiers, test data, and other non-authentication contexts.