CodeCraft

UUID Generator

Bulk generate UUID v4, powered by crypto.randomUUID(). Cryptographically secure.

How to Use

  1. Set the desired number of UUIDs to generate (1–1000).
  2. Optionally enable Uppercase output.
  3. Click Generate to create the UUIDs.
  4. Click Copy All to get all UUIDs (one per line), or hover a row and click to copy a single one.

About UUID Generator

UUID (Universally Unique Identifier) is a 128-bit identifier standardized as RFC 4122, designed to be unique across space and time without requiring central coordination. A UUID v4 contains 122 bits of cryptographically secure random data, making collisions virtually impossible (even at 1 billion UUIDs per second for 1 billion years, collision probability is ~50%). UUIDs are used as database primary keys, session identifiers, file names, and any situation where globally unique IDs are needed without a central authority. This generator uses the browser's built-in Web Crypto API for cryptographically secure generation -- all processing happens locally in your browser.

Use Cases

Database Primary Keys

Generate unique identifiers for distributed database records without coordination between nodes.

API Request Tracing

Assign UUIDs to requests for end-to-end tracing across microservices (correlation IDs).

Session Identifiers

Create cryptographically random session tokens that are virtually impossible to guess.

File Naming

Use UUIDs for uploaded file names to prevent collisions and avoid exposing sequential patterns.

Examples

Input
(generate)
Output
f47ac10b-58cc-4372-a567-0e02b2c3d479

UUID v4 format: 8-4-4-4-12 hex characters. The '4' in position 13 indicates version 4 (random).

Input
Batch: 5
Output
5 unique UUIDs, one per line

Each generated UUID has a collision probability of ~1 in 5.3×10³⁶ — effectively zero.

Common Pitfalls & Edge Cases

  • ⚠UUID v4 is random, not sequential. Don't use it where ordered inserts matter (e.g., clustered DB indexes).
  • ⚠UUIDs are 128 bits (36 chars with hyphens). Consider compact formats (no hyphens, base62) for URLs.
  • ⚠Not all UUID versions are random — v1 includes MAC address and timestamp (privacy concern).
  • ⚠Crypto.getRandomValues() is required for secure generation. This tool uses the Web Crypto API.

🔒 Data Privacy

UUIDs are generated using the Web Crypto API (crypto.getRandomValues) entirely in your browser. No server communication occurs.

Standards & References

Frequently Asked Questions

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