UUID Generator

Generate cryptographically secure UUID v4 identifiers. Bulk generation up to 100, with uppercase and hyphen options.

Generate cryptographically secure UUID v4 identifiers

Generated UUIDs (1)
UUIDs are generated locally using the Web Crypto API (crypto.randomUUID). No data is sent to any server.

How to Use This Tool

  1. 1

    Set the quantity

    Enter how many UUIDs you need — from 1 to 100 at a time.

  2. 2

    Choose formatting options

    Toggle uppercase (A-F vs a-f) and hyphens (with or without dashes) to match your use case.

  3. 3

    Generate UUIDs

    Click the Generate button to create fresh UUID v4 values using the Web Crypto API.

  4. 4

    Copy to clipboard

    Click any individual UUID to copy it, or use 'Copy All' to copy the entire batch separated by newlines.

Frequently Asked Questions

What is a UUID v4?
UUID v4 (Universally Unique Identifier version 4) is a 128-bit identifier generated using random or pseudo-random numbers. It follows the format xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx where 4 indicates the version and y is 8, 9, a, or b.
How unique are UUID v4 values?
With 122 random bits, there are approximately 5.3 × 10³⁶ possible UUID v4 values. The probability of a collision is astronomically low — you would need to generate about 2.71 quintillion UUIDs to have a 50% chance of one duplicate.
Are these UUIDs cryptographically secure?
Yes. This tool uses the Web Crypto API (crypto.randomUUID()), which provides cryptographically strong random values. They are suitable for security-sensitive applications.
Should I use hyphens or not?
Standard UUID format includes hyphens (e.g., 550e8400-e29b-41d4-a716-446655440000). Removing hyphens is common in databases and URLs where a compact format is preferred. Both are valid.