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Random and UUID Generator

Generate random numbers, strings and UUID v4 values using cryptographically secure methods. Bulk generation supported.

Random Number Generator
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Max
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Bulk Random Numbers
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Unique only
Random String Generator
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Character Sets
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Bulk Strings
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UUID v4 Generator
Click Generate
Bulk UUIDs
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About the Random and UUID Generator

This tool uses the browser crypto.getRandomValues() API for all generation, making all outputs cryptographically random and suitable for security contexts. UUID v4 values follow RFC 4122 and are generated with the correct version and variant bits set. They are suitable for use as database primary keys, session identifiers, API tokens and distributed system identifiers.

The bulk generation feature lets you produce up to 500 UUIDs or random strings at once, useful for seeding test databases, generating batches of unique codes or creating test data sets. The unique-only option for bulk number generation ensures no duplicates appear in the output.

Common Use Cases

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    Database primary keys. UUID v4 values are widely used as primary keys in distributed databases where auto-increment integers would cause conflicts across multiple nodes.
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    API tokens and session IDs. Generate cryptographically secure random strings for API keys, session tokens, CSRF tokens and one-time codes.
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    Test data generation. Generate bulk random numbers or strings to populate test databases, mock API responses or load test scenarios.
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    Random sampling. Use the unique-only bulk mode to generate random samples from a numbered set without duplicates, for lottery draws, random selection or A/B test assignment.

Frequently Asked Questions

What makes crypto.getRandomValues secure?
It uses the OS-level cryptographically secure pseudorandom number generator (CSPRNG), seeded with true entropy from hardware sources. Unlike Math.random() which is predictable, crypto.getRandomValues() output cannot be predicted even if previous outputs are known.
Are UUID v4 values truly unique?
UUID v4 values have 122 bits of randomness. The probability of generating two identical UUIDs is approximately 1 in 5.3 undecillion (5.3 x 10^36). For practical purposes, they are unique. UUID v4 is the recommended format for most use cases.
What is the difference between UUID and GUID?
GUID (Globally Unique Identifier) is Microsoft's term for UUID. They are the same format: 32 hex digits in the pattern 8-4-4-4-12. A UUID v4 and a GUID v4 are interchangeable.

Security and Test Data Limits

The generator is useful for test data, UUIDs, sample identifiers, temporary codes and random strings. For production secrets, follow your organisation's security process, store secrets in a password manager or secrets vault, and avoid sharing generated tokens through email, chat or screenshots.

Random strings and UUIDs are not the same as managed authentication. A secure application still needs expiry rules, access control, logging, rotation and safe storage. Use this page as a generation helper, not as a complete identity or key-management system.