UUID Generator

UUID Generator — Free RFC 4122 Version 4 Unique Identifier Creator

Generate cryptographically secure Version 4 Universally Unique Identifiers (UUID / GUID) directly in your web browser. Powered by Web Crypto APIs (crypto.getRandomValues), this tool creates random 128-bit hex UUIDs locally without network calls.

Standards & Technical Specifications

• RFC 4122 Specification: A Universally Unique IDentifier (UUID) URN Namespace.
• W3C Web Crypto API: Cryptographically secure pseudo-random number generator (CSPRNG).

How to Generate UUIDs Step-by-Step

1. 1Select Quantity: Choose how many UUIDs to generate (1 to 1000).
2. 2Toggle Formatting: Choose uppercase/lowercase or hyphenation parameters.
3. 3Click Generate UUIDs: Compute CSPRNG 128-bit hex arrays.
4. 4Copy or Export: Copy generated GUIDs to clipboard or export as text.

Structure of a Version 4 UUID

A standard RFC 4122 v4 UUID follows the format xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx (36 characters total including hyphens):

• The 4 at position 13 indicates Version 4 (randomly generated).
• The y position holds variant bits (8, 9, a, or b representing binary 10xx).

$$\text{Entropy} = 122 \text{ random bits} \implies 2^{122} \approx 5.3 \times 10^{36} \text{ unique combinations}$$

Practical Developer Use Cases

• Database Primary Keys: Generate unique string keys for distributed database records without central coordinator lock overhead.
• Session Tokens & API Tracking: Assign unique request IDs to HTTP API calls and user sessions.
• File Naming: Assign collision-proof unique names to user uploaded files.

Frequently Asked Questions (FAQs)

Are generated UUIDs unique across the world?

Yes. The probability of generating duplicate v4 UUIDs is $1$ in $2^{122}$ ($approx 5.3 \times 10^{36}$), making collision practically impossible.

Related Developer Utilities

• Hash Generator: Create SHA-256 and MD5 cryptographic hashes.

Standardized Developer Tools & Cryptographic Utilities

Modern web development and software engineering require reliable, secure utilities for formatting JSON payloads, inspecting JWT authentication tokens, encoding Base64 data strings, and generating cryptographically secure UUIDs and hashes.

Our suite of developer tools is built strictly to comply with RFC and IETF internet standards.

Technical & Cryptographic Compliance:

• RFC Standards Compliance: Adheres to RFC 8259 (JSON), RFC 7519 (JWT), RFC 4122 (UUID v4), and RFC 4648 (Base64).
• Native Web Crypto API Integration: Uses hardware-accelerated, cryptographically secure pseudo-random number generators (CSPRNG) and SHA/MD5 hashing algorithms.
• Client-Side Security: Secrets, API keys, JWT tokens, and private database queries are processed entirely inside browser memory, ensuring development credentials are never exposed over network logs.

RFC-Compliant Developer Tools & Cryptographic Utilities

Software engineering and modern web development require reliable, secure utilities for formatting JSON payloads, inspecting JWT authentication tokens, encoding Base64 data strings, and generating cryptographically secure UUIDs and hashes.

Technical & Cryptographic Compliance:

• RFC Standards Compliance: Adheres to RFC 8259 (JSON), RFC 7519 (JWT), RFC 4122 (UUID v4), and RFC 4648 (Base64).
• Native Web Crypto API Integration: Uses hardware-accelerated, cryptographically secure pseudo-random number generators (CSPRNG) and SHA/MD5 hashing algorithms.
• Client-Side Security: Secrets, API keys, JWT tokens, and private database queries are processed entirely inside browser memory, ensuring development credentials are never exposed over network logs.

RFC-Compliant Developer Tools & Cryptographic Utilities

Software engineering and modern web development require reliable, secure utilities for formatting JSON payloads, inspecting JWT authentication tokens, encoding Base64 data strings, and generating cryptographically secure UUIDs and hashes.

Technical & Cryptographic Compliance:

• RFC Standards Compliance: Adheres to RFC 8259 (JSON), RFC 7519 (JWT), RFC 4122 (UUID v4), and RFC 4648 (Base64).
• Native Web Crypto API Integration: Uses hardware-accelerated, cryptographically secure pseudo-random number generators (CSPRNG) and SHA/MD5 hashing algorithms.
• Client-Side Security: Secrets, API keys, JWT tokens, and private database queries are processed entirely inside browser memory, ensuring development credentials are never exposed over network logs.