UUID Generator
Generate UUID v1 and UUID v4 identifiers instantly. Copy a single UUID or generate multiple at once for databases, APIs, testing, and development use.
UUID Generator
Generate random UUID v4 values instantly for apps, databases, APIs, sessions, and unique identifiers.
Settings
Generate between 1 and 100 UUIDs at a time.
Overview
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Generated UUIDs
Copy one or export the whole list.
Common use cases
What this tool does
This tool generates Universally Unique Identifiers (UUIDs) directly in your browser. Choose between version 1 (timestamp-based) and version 4 (random). Generated UUIDs can be copied one-click and used immediately in your database schemas, API payloads, mock data, or test fixtures.
When to use it
Use UUIDs when building APIs, setting up database primary keys for distributed systems, generating unique session tokens, creating mock data for testing, or anywhere you need a reliably unique identifier without a central counter or registry.
Frequently Asked Questions
What is a UUID?
A UUID (Universally Unique Identifier) is a 128-bit identifier formatted as 32 hexadecimal characters in five groups separated by hyphens — for example: 550e8400-e29b-41d4-a716-446655440000. It is designed to be globally unique.
What is the difference between UUID v1 and UUID v4?
UUID v1 is generated using the current timestamp and the device's MAC address, meaning it can be traced back to when and where it was created. UUID v4 is fully random with no time or machine information embedded — it is more privacy-friendly and widely preferred.
Can two UUIDs ever be the same?
The probability is astronomically low. A UUID v4 has 2^122 possible values, making a collision practically impossible in any real-world system.
When should I use a UUID instead of an auto-increment ID?
Use UUIDs when you need IDs that are unique across multiple databases, services, or devices — such as in distributed systems, APIs, microservices, and multi-tenant applications. Auto-increment integers are fine for simple single-database apps.
Can I use this UUID in a database primary key?
Yes. UUIDs are commonly used as primary keys in PostgreSQL, MySQL, MongoDB, and other databases. Some databases have a native UUID type for efficient storage.