UUID Generator (v4 & v7)
Generate random UUID v4 and time-ordered UUID v7 identifiers locally using native browser crypto primitives with bulk and case options.
Generated V4 Identifiers
0 UUIDsℹ️ Understanding UUID v4 vs. UUID v7 (RFC 9562)
Generated purely from 122 bits of cryptographic pseudo-randomness. Completely non-sequential, with virtually zero collision probability (1 in 2¹²²).
Best for: Temporary tokens, session identifiers, and security nonces where chronological order must be kept hidden.
Combines a 48-bit Unix timestamp in milliseconds with 74 bits of entropy. Naturally sortable chronologically, avoiding database B-tree index fragmentation.
Best for: Database primary keys (PostgreSQL, MySQL), event streams, and distributed message tracking.
How It Works
- Generates RFC 4122 random UUID v4 using native Web Crypto crypto.randomUUID().
- Generates RFC 9562 UUID v7 embedding 48-bit millisecond unix timestamps for optimal database index clustering.
- Supports bulk batch generation (up to 50 UUIDs) with uppercase/lowercase formatting.
Practical Example
Frequently Asked Questions
When should I use UUID v7 over v4?
UUID v7 is ideal for database primary keys because its chronological ordering prevents B-Tree index fragmentation while retaining global uniqueness.
Related Tools
Secure Password Generator
Generate cryptographically secure passwords locally via crypto.getRandomValues() with accurate real-time entropy scoring and zero server transmissions.
Cryptographic Hash Generator
Compute secure cryptographic message digests client-side using native window.crypto.subtle and pure JS MD5 with legacy safety indicators.
Base64 Encoder & Decoder
Encode or decode text to Base64 ASCII strings with full multi-byte Unicode UTF-8 handling.