Generate cryptographically secure random strings from preset or custom character sets. Choose hex, alphanumeric, alphabetic, numeric, Base64, or URL-safe. Bulk generate up to 100 strings.
0123456789abcdef
LevnTools Random String Generator lets you secure and verify your data directly in your browser. Everything runs locally in your browser — your sensitive data never leave your device. Unlike cloud-only alternatives that require uploads and accounts, this tool is completely free with no usage limits or watermarks. It is designed for developers generating secure tokens, IT professionals verifying file integrity, security-conscious users protecting passwords — anyone who needs a fast, reliable security tool without the overhead of installing software. Just open the page and start working.
Random String Generator is used by a wide range of people. Explore how different groups use this tool:
Generate strong passwords and passphrases with crypto randomness.
Analyze password strength with crack time estimates and tips.
Encrypt and decrypt text with AES-256-GCM and a password.
Format, beautify, minify, and validate JSON with syntax highlighting.
Convert text to camelCase, snake_case, kebab-case, and 7 more.
Six presets are available: Hex (0-9, a-f), Alphanumeric (A-Z, a-z, 0-9), Alphabetic (A-Z, a-z), Numeric (0-9), Base64 (A-Z, a-z, 0-9, +, /), and URL-safe (A-Z, a-z, 0-9, -, _). You can also define a completely custom character set.
Yes. All random numbers come from the Web Crypto API (crypto.getRandomValues), which is a CSPRNG (Cryptographically Secure Pseudo-Random Number Generator). Math.random() is never used.
URL-safe strings use characters that do not need encoding in URLs (letters, digits, hyphen, underscore). They are commonly used for API tokens, session IDs, and unique identifiers in web applications.
The slider goes up to 256 characters, which covers virtually all use cases for tokens, keys, and identifiers. For longer strings, you can generate multiple and concatenate them.
Completely. Strings are generated locally in your browser using the Web Crypto API. Nothing is sent to any server. The tool works fully offline once loaded.