UUID v4 generator

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Generate UUID v4 online instantly for databases, APIs, and applications that require unique identifiers. This UUID v4 generator creates random 128-bit values in the standard format xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx, ensuring global uniqueness. Common long-tail use cases include UUID v4 generator online, create random GUID, generate UUID for database, and secure UUID v4 string generator.

What is UUID v4?

UUID v4 (Universally Unique Identifier, version 4) is a 128-bit identifier generated using random numbers. It is formatted as five groups of hexadecimal digits separated by hyphens (36 characters total). Example: 550e8400-e29b-41d4-a716-446655440000. Unlike sequential IDs, UUID v4 offers extremely low collision probability, making it perfect for distributed systems and API keys.

Why use a UUID v4 Generator?

Guaranteed uniqueness: With 122 random bits, the chance of duplicate UUIDs is negligible.
Decentralized generation: No central authority or incremental counters needed—any system can generate UUIDs independently.
Cross-platform compatibility: UUID v4 is widely supported across programming languages and databases.
Security: Randomness makes UUID v4 harder to predict compared to sequential IDs.

How to use the UUID v4 Generator

Click “Generate” to instantly create a new UUID v4.
Copy the result into your database, API configuration, or application code.
Batch mode: Generate multiple UUIDs at once if you need bulk identifiers.

Who should use it?

Developers creating unique identifiers for records, sessions, or objects.
Database administrators needing primary keys without collisions.
API architects issuing tokens, keys, or request IDs.
QA & testers generating mock data with guaranteed uniqueness.

Best practices

Use UUID v4 for uniqueness, but avoid exposing them directly if sensitive (they are not encrypted).
Check performance: UUIDs are larger than integers; indexing them may impact database speed.
Prefer lowercase UUIDs for consistency across systems.
Validate format with regex ^[0-9a-f]{8}-[0-9a-f]{4}-4[0-9a-f]{3}-[89ab][0-9a-f]{3}-[0-9a-f]{12}$.

Examples

Generated UUID v4 values

1. 3fa85f64-5717-4562-b3fc-2c963f66afa6
2. 550e8400-e29b-41d4-a716-446655440000
3. f47ac10b-58cc-4372-a567-0e02b2c3d479

Code snippets

// JavaScript
crypto.randomUUID(); 
// Example: "9a1f9e90-72a2-4c31-8ff1-9f39d6ecbfa2"

// Python
import uuid
print(uuid.uuid4())

// Node.js
const { randomUUID } = require('crypto');
console.log(randomUUID());

// PHP
echo uuid_create(UUID_TYPE_RANDOM);

// Go
import "github.com/google/uuid"
fmt.Println(uuid.New())