Random String Generator
Generate random strings for IDs, test data, coupon codes, salts and secrets. Choose alphanumeric, letters, numbers, hex, URL-safe, Base58 or your own character set, set the length and quantity, add a prefix, and copy them all — generated securely in your browser.
Pick a character set and length, choose how many strings to generate, and optionally add a prefix. Each character is chosen uniformly with crypto.getRandomValues, and the tool shows how many bits of randomness each string carries, so you know whether it's suitable as a secret (128+ bits) or just a unique ID.
62 characters × 32 = 191 bits of randomness per string — enough for secret tokens.
Zero Server Uploads
Files process in local RAM
Instant WASM Speed
No waiting queues or lags
Unlimited Batching
Convert files without limits
Suggest a Feature or Improvement for Random String Generator
Need custom options, higher limits, or extra format support? Let our engineering team know!
How to use Random String Generator
- 1Choose the characters to use, or enter a custom set.
- 2Set the length and how many strings you need.
- 3Add a prefix if you want one (like ref_).
- 4Copy one string or all of them.
Choosing a character set
Alphanumeric (62 characters) is safe almost everywhere. Hex is ideal for keys and hashes. URL-safe adds - and _ so strings can go straight into URLs. Base58 drops 0, O, I and l so codes are easy to read aloud or type — it's what Bitcoin addresses use.
Each character from a set of N adds log2(N) bits: about 5.95 bits for alphanumeric and 4 bits for hex. 22 alphanumeric characters give 128 bits.
Random isn't always secret
For API keys and session tokens use at least 128 bits of randomness, which the tool indicates. For secrets with a specific format, the Secure Token Generator and API Key Generator produce hex, Base64url and prefixed keys directly.
Frequently Asked Questions
Are these strings cryptographically secure?
Yes. They use the browser's cryptographically secure random number generator with rejection sampling, so there's no modulo bias.
Can I generate thousands at once?
You can generate up to 100 at a time and click New for more. Every batch is independent.
Is my data sent to your server?
No. This tool runs entirely in your browser using the Web Crypto API and JavaScript. Nothing you type or generate is uploaded, logged or stored.
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