UUID v4 Generator
Generate random UUID v4 identifiers with RFC 4122 compliance and collision-resistant generation. Perfect for database keys, unique identifiers, and distributed system applications with cryptographic randomness.
How it works:
- • Uses cryptographically secure random number generation
- • Generates 128-bit unique identifiers
- • Follows RFC 4122 v4 specification
- • Format: 8-4-4-4-12 hexadecimal groups
🔒 Privacy & Security:
All UUIDs are generated locally in your browser using the Web Crypto API. No data is sent to our servers or stored anywhere. Your generated UUIDs will be lost when you close this browser tab, ensuring complete privacy and security.
Complete Guide: UUID v4 Generator
Everything you need to know about using this tool effectively
The UUID v4 Generator creates version 4 UUIDs that comply with RFC 4122. Version 4 UUIDs are generated from random numbers, with the version and variant bits set according to the standard. The tool uses the browser's crypto.randomUUID API for secure randomness. All processing happens in the browser.
This tool generates UUIDs using crypto.randomUUID, which produces RFC 4122 v4 compliant identifiers. Each UUID is a 128-bit value with 122 random bits. The tool formats the output with hyphens in the standard 8-4-4-4-12 pattern.
Database primary keys
Generate UUIDs for distributed database systems where auto-increment IDs are not suitable.
API authentication tokens
Create unique tokens for API authentication and session management.
Distributed system identifiers
Generate IDs that are unique across multiple servers without coordination.
File naming
Use UUIDs as file names to prevent naming conflicts.
Set count
Choose how many UUIDs to generate.
Generate
Click Generate to create the UUIDs.
Copy
Click any UUID to copy it to the clipboard.
Download
Download all UUIDs as a text file.
UUID v4 is the most commonly used version because of its randomness.
Always use the full 36-character format including hyphens.
For database storage, some prefer storing as binary(16) to save space.
UUIDs sort poorly in databases. Consider using UUID v7 for time-ordered IDs.
What makes v4 different from other UUID versions?
UUID v4 is generated from random numbers (122 random bits). Other versions use timestamps (v1, v7) or names (v3, v5).
Is it RFC 4122 compliant?
Yes. The generated UUIDs follow the RFC 4122 version 4 specification with correct version and variant bits.
Is my data sent to a server?
No. All generation happens in your browser. Nothing is transmitted.
Can I generate many at once?
Yes. Generate batches of UUIDs in a single operation.
Is crypto.randomUUID widely supported?
Yes. It is supported in all modern browsers (Chrome, Firefox, Safari, Edge).