UUID / GUID Generator & Validator
Generate cryptographically secure UUID v4, time-based v1, or compact NanoIDs in bulk with custom casing, hyphens, and JSON formatting.
Bulk UUID / GUID Generator
Generate RFC 4122 compliant unique identifiers using Web Crypto API.
UUID & GUID Specifications Explained
UUID v4 (Random)
122 bits of cryptographically strong entropy
Version 4 UUIDs are generated using pseudo-random numbers from crypto.getRandomValues(). The probability of a collision is virtually zero.
UUID v1 (Time-based)
Current timestamp + MAC node address
Version 1 UUIDs are generated from the current 60-bit timestamp and node identifier, ensuring chronological sortability.
UUID vs. GUID
Identical 128-bit RFC 4122 standard
GUID (Globally Unique Identifier) is Microsoft's terminology for UUID (Universally Unique Identifier). Both share the identical 8-4-4-4-12 hex layout.
Frequently Asked Questions
Are these UUIDs cryptographically secure?
Yes! All UUIDs are generated using the browser's native window.crypto.randomUUID() or crypto.getRandomValues() CSPRNG APIs.
What is the likelihood of two UUID v4 values colliding?
To have a 50% chance of a single collision, you would need to generate approximately 2.71 quintillion UUIDs (2.71 × 10^18), which is virtually impossible under real-world computing conditions.
Can I inspect an existing UUID?
Yes! Click the 'UUID Validator & Inspector' tab to paste any identifier and inspect its RFC 4122 compliance, version number, and variant.