Text & Code

Random String Generator

Generate cryptographically random strings with strength meter, batch generation, and character set controls.

Your files stay on your device - processed locally via WebAssembly, never uploaded

Mode

Length16

Character Sets

Generate Count1

Strings are generated using your browser's crypto.getRandomValues() cryptographic random number generator. Nothing is sent to any server.

🔒 All generation happens in your browser. Nothing is sent anywhere.

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Copy this code to add the Random String Generator to your site for free. It runs entirely in your visitors' browsers - no API key, no usage limits.

<iframe src="https://optipix.art/embed/random-string-generator" width="100%" height="600" style="border:1px solid #e4e4e7;border-radius:8px;" title="Random String Generator by OptiPix" loading="lazy"></iframe>
<p style="font-size:12px">Free tool by <a href="https://optipix.art/random-string-generator">OptiPix Random String Generator</a></p>

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About Random String Generator

Last updated: May 2026

OptiPix Random String Generator creates cryptographically secure random strings using your browser's crypto.getRandomValues() API. Adjust length from 4 to 128 characters using a slider. Toggle character sets: uppercase (A-Z), lowercase (a-z), numbers (0-9), and symbols. Exclude ambiguous characters (0/O, 1/l/I) for readability. The entropy-based strength meter rates strings from Weak to Very Strong. Generate pronounceable strings using consonant-vowel patterns for easier memorization, or switch to passphrase mode to generate 4-8 random words separated by hyphens. Batch generate up to 20 strings at once. Copy individual strings or all at once. A new string is auto-generated on every page load. Everything runs locally - nothing is sent to any server.

How It Works

The tool builds a character set from your selected toggles, generates a Uint32Array of the desired length using crypto.getRandomValues(), then maps each random number to a character using modulo selection. Strength is calculated from Shannon entropy: bits = length × log₂(charsetSize).

Use Cases

  • Generate random strings for developer testing and API keys
  • Create secure tokens for authentication systems
  • Generate random identifiers for database seeding
  • Create strong, unique strings for configuration secrets
  • Generate passphrases that are easy to remember

You Might Also Like

If you find Random String Generator useful, check out these related tools: UUID Generator, Hash Generator, and Base64 Text Encoder / Decoder. All tools run entirely in your browser with no uploads or signups required.

Frequently Asked Questions

How are the strings generated?
Using your browser's crypto.getRandomValues() API, which provides cryptographically secure random numbers. This is the same randomness source used for TLS encryption.
What is the strength meter based on?
Entropy in bits, calculated as length × log₂(charset size). Under 28 bits is Weak, 28-35 is Fair, 36-59 is Strong, and 60+ is Very Strong.
What is passphrase mode?
Instead of random characters, it generates 4-8 random words separated by hyphens (like 'correct-horse-battery-staple'). Passphrases are easier to remember while still being secure.
Can I generate multiple strings at once?
Yes. Use batch generation to create up to 20 strings at once with identical settings. Copy all with one click.
Is anything sent to a server?
No. All generation uses your browser's built-in cryptographic random number generator. Nothing is transmitted over the network.

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