Include Characters
What is a Random String Generator?
A random string generator creates unpredictable sequences of characters by combining lowercase letters, uppercase letters, numbers, and special symbols. This tool uses the browser's Web Crypto API (crypto.getRandomValues) to produce cryptographically secure random numbers (CSPRNG). Unlike Math.random(), which relies on a predictable pseudo-random algorithm, CSPRNG draws from the operating system's entropy sources, making the output virtually impossible to predict. You can generate strings from 1 to 256 characters long, and create up to 100 strings at once for batch operations.
Common Use Cases
Temporary Passwords — Quickly create initial passwords for user registration or password reset flows. A combination of uppercase, lowercase, numbers, and symbols with at least 12 characters is recommended for strong security.
API Keys and Tokens — Generate API keys, session tokens, CSRF tokens, and other secrets used for server-to-server communication. For these use cases, alphanumeric strings of 32 characters or more are standard practice.
Test Data — Fill development and staging environments with dummy data quickly. Generating multiple random strings at once saves significant time when populating databases or testing input validation.
Unique Identifiers — Create short, human-readable unique codes such as invitation codes, coupon codes, or order reference numbers that are distinct from standard UUIDs.
Security Tips
This tool leverages crypto.getRandomValues, which is a cryptographically secure pseudo-random number generator (CSPRNG) provided by the browser. This is fundamentally different from Math.random(), a basic pseudo-random number generator (PRNG). With PRNG, knowing the internal seed state allows an attacker to predict future outputs, whereas CSPRNG relies on OS-level entropy sources that make prediction practically infeasible. However, securely transmitting and storing the generated strings remains your responsibility. Always hash passwords with algorithms like bcrypt or Argon2 before storing them, manage API keys through environment variables, and never share sensitive strings in plaintext.
Frequently Asked Questions
Are the generated strings truly secure?▼
Yes. This tool uses the Web Crypto API (crypto.getRandomValues), which provides cryptographically secure random numbers. The output is suitable for passwords, tokens, and other security-sensitive purposes.
What is the recommended password length?▼
A minimum of 12 characters combining uppercase, lowercase, numbers, and symbols is recommended. For high-security applications, use 16 characters or more.
Are the generated strings sent to any server?▼
No. All generation happens entirely within your browser. No data is transmitted to any server, and the tool works even without an internet connection.
How is this different from Math.random()?▼
Math.random() uses a predictable pseudo-random number generator (PRNG) that can be reverse-engineered. This tool uses a cryptographically secure random number generator (CSPRNG) backed by the operating system entropy pool, making the output far more secure and unpredictable.
What is Random String Generator?
Generate cryptographically secure random strings instantly. Choose length, include uppercase, lowercase, numbers, and symbols. Perfect for creating strong passwords, API keys, and security tokens.