A UUID (Universally Unique Identifier) is a 128-bit label used to identify information in computer systems. The standard form uses 32 hexadecimal digits in groups separated by hyphens: 550e8400-e29b-41d4-a716-446655440000.

UUID v4 is randomly generated. It has 122 bits of randomness (6 bits are version/variant identifiers). The collision probability is astronomically low.

What is the probability of a UUID collision?

Generating 1 billion UUIDs per second for 100 years has only a 50% chance of a single collision. For practical purposes, UUID v4 collisions are impossible.

What is the difference between UUID v1 and v4?

UUID v1 is based on the current time and MAC address. UUID v4 is fully random. v4 is preferred for privacy since v1 can reveal your machine's MAC address.

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UUID Generator

Generate UUID v4 values using the Web Crypto API. Supports bulk generation, uppercase, and no-hyphens options.

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Version

v4 (random)

Count (1–100)

UppercaseHyphens

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What is UUID Generator?

UUID Generator is a free online tool that creates UUID v4 values using the browser's crypto.randomUUID() API (or a polyfill using crypto.getRandomValues). Generate 1–100 UUIDs at once with options for uppercase and hyphens.

How It Works

UUID v4 uses 122 bits of cryptographically random data. The tool uses crypto.randomUUID() if available, otherwise it generates 16 random bytes using crypto.getRandomValues() and formats them as a UUID per RFC 4122: version bits are set to 4 and variant bits to 10xx.

How to Use

1
Choose UUID version
Select UUID v4 (random) for most use cases, or v1 (time-based) for ordered identifiers.
2
Set quantity
Enter how many UUIDs to generate — from 1 to 1000 at a time.
3
Generate
Click "Generate UUIDs". All values are created using cryptographically secure random number generation.
4
Copy all
Click "Copy All" to copy the full list to your clipboard for use in databases, code, or configuration files.

Who Uses This Tool

🗄️

Database Primary Keys

Generate UUID v4 values to use as primary keys in distributed databases where auto-increment would cause conflicts.

📦

Object Identity in Code

Create UUIDs for in-memory objects, components, or React keys to guarantee uniqueness without a central registry.

🔗

API Resource Identifiers

Use UUIDs as resource IDs in REST APIs to prevent sequential enumeration attacks on endpoints.

🧪

Test Data Generation

Generate batches of UUIDs to populate test fixtures with realistic-looking unique identifiers.

📁

Unique File Naming

Use UUIDs as filenames for user-uploaded files to prevent collisions on shared storage buckets.

🔐

Session Token Seeding

Generate a UUID v4 as the base for session tokens or correlation IDs in distributed tracing systems.

Why Choose This Tool

RFC 4122 Compliant

Generated UUIDs strictly follow RFC 4122 v4 format with correct version (4) and variant (10xx) bits set.

Bulk Generation

Generate up to 100 UUIDs at once with a single click for batch operations and test data creation.

Cryptographically Random

Uses crypto.randomUUID() or crypto.getRandomValues() for 122 bits of true randomness per UUID.

Format Options

Toggle uppercase output and hyphen removal to match the format expected by your specific database or system.

Copy All Feature

Copy every generated UUID to the clipboard as a newline-separated list for easy pasting into scripts or seed files.

Instant and Private

All UUIDs are generated in your browser with no server calls, ensuring fast results and complete privacy.

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Key Benefits

Generates standards-compliant UUID v4
Uses the secure native Web Crypto API
Generate 1–100 UUIDs at once
Toggle uppercase and hyphens
Copy all or copy individual UUIDs

Frequently Asked Questions

Also Known As

uuid generator online freeuuid v4 generator browsergenerate guid online toolbulk uuid generator freerandom uuid generator no installonline uuid creator toolguid generator online freegenerate multiple uuids at once

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