Random String
Generate random strings with custom patterns — alphanumeric, alphanumeric with symbols, or custom charset.
Input
Output
Ready — enter input to start
Frequently Asked Questions
What are random strings used for in development?
Random strings serve many purposes: session tokens for user authentication, API keys for service identification, test data for database seeding, coupon codes, one-time passwords, and cryptographic nonces. Each use case has different requirements for length and character set.
What character sets are available?
The tool supports alphanumeric (a-z, A-Z, 0-9), alpha only (letters), uppercase alphanumeric, numeric only, and hexadecimal (0-9, a-f). You can also specify a custom character set to include only the characters your system allows, such as avoiding confusing characters like uppercase O and lowercase l.
How many strings can I generate at once?
You can specify the count parameter in your input, up to 100 strings per generation. Use the format count:10 to generate 10 strings. Each string is generated using cryptographically secure random numbers, ensuring true unpredictability for security-sensitive applications.
What entropy level do I need for security tokens?
Session tokens require at least 128 bits of entropy to resist brute force attacks. With alphanumeric characters (62 options per position), a 22-character string provides sufficient entropy. For encryption keys, use longer strings matching your algorithm requirements, such as 256 bits for AES-256.
Is the random generation cryptographically secure?
Yes. The tool uses the browser's crypto.getRandomValues() API which provides cryptographically secure random numbers suitable for security-sensitive applications. This is not the same as Math.random(), which is predictable and should not be used for tokens or keys.
Is my data sent to a server?
No. All string generation happens locally in your browser using cryptographically secure random number generation. Generated strings never leave your device and are not stored or transmitted to any server.