ToolHarbor

UUID Generator

Generate random UUIDs (v4) instantly. Free online tool with bulk generation and formatting options.

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Features

  • Generate cryptographically random UUIDs
  • Bulk generation (up to 100 at once)
  • Uppercase and no-dashes formatting options
  • Copy individual or all UUIDs
  • Works offline using Web Crypto API
  • RFC 4122 compliant version 4 UUIDs

How to Use

  1. 1Select how many UUIDs you need (1 to 100)
  2. 2Choose formatting options: uppercase or no dashes
  3. 3Click "Generate" to create new UUIDs
  4. 4Click "Copy" next to any UUID to copy it
  5. 5Use "Copy All" to copy all UUIDs at once

Examples

Standard UUID v4

Input

Generate 1 UUID

Output

550e8400-e29b-41d4-a716-446655440000
Uppercase format

Input

Generate with uppercase option

Output

550E8400-E29B-41D4-A716-446655440000
Without dashes

Input

Generate with no-dashes option

Output

550e8400e29b41d4a716446655440000

What is a UUID?

A UUID (Universally Unique Identifier), also known as GUID (Globally Unique Identifier), is a 128-bit identifier that is guaranteed to be unique across all space and time. UUIDs are widely used in software development for database primary keys, session identifiers, transaction IDs, and distributed system coordination. This UUID generator creates random identifiers you can use immediately in your projects.

This tool generates version 4 UUIDs, which are created using random or pseudo-random numbers. The format follows RFC 4122: xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx, where x is any hexadecimal digit and y is one of 8, 9, A, or B. The "4" in the third group indicates version 4, and y indicates the UUID variant. This standardized format is recognized by virtually all programming languages and databases.

UUID v4 uses 122 random bits, providing approximately 5.3 × 10^36 possible unique values. The probability of generating two identical UUIDs is astronomically low — you would need to generate 1 billion UUIDs per second for about 85 years to have a 50% chance of a collision. This makes UUIDs perfect for scenarios where coordination between systems is impractical.

Our UUID generator supports bulk generation of up to 100 UUIDs at once, with options for uppercase formatting and removing dashes. Whether you need a single unique identifier or a batch for seeding a database, this tool handles it instantly. The generated UUIDs are RFC 4122 compliant and suitable for production use.

Modern browsers provide the crypto.randomUUID() method which uses a cryptographically secure random number generator (CSPRNG). This UUID generator leverages that API when available, falling back to a secure alternative for older browsers. All UUIDs are generated entirely in your browser — nothing is sent to any server, ensuring complete privacy.

Frequently Asked Questions

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