UUID Generator

About the UUID Generator

A UUID (Universally Unique Identifier) is a 128-bit value used to identify resources without central coordination. The most common form is UUID v4, which is generated from random or pseudo-random numbers and is typically written as 36 characters (e.g. 550e8400-e29b-41d4-a716-446655440000) with hyphens. UUIDs are used in databases, APIs, distributed systems, and file or session IDs. A UUID generator creates one or more such identifiers so you can assign unique IDs in your applications.

How to Use

Choose how many UUIDs you need (e.g. 1 or 10), then click generate. The tool displays the UUID(s); you can copy one or all. Generated IDs are suitable for non-security purposes (e.g. primary keys, request IDs). For security-sensitive identifiers (e.g. tokens), use a cryptographically secure source as specified by your platform.

• Set the number of UUIDs and click Generate.
• Copy the UUID(s) for use in your system.

How to Use This UUID Generator

Choose the number of UUIDs to generate and click generate. The UUID Generator outputs UUID v4 (random) identifiers in standard format (e.g. 550e8400-e29b-41d4-a716-446655440000). Use them for primary keys, API IDs, or session tokens. Copy and paste into your application. This tool is for informational and development use only; for security-sensitive IDs follow your platform's guidance.

Where UUIDs Are Used

UUIDs are used for primary keys in databases, request or trace IDs in APIs, file and object names in storage, and session or correlation IDs. They allow different systems to create IDs without contacting a central server. The collision probability is extremely low for v4. Results are for informational and development use.

When to Use UUIDs

Use UUIDs when you need globally unique identifiers across distributed systems, when merging data from multiple sources without ID clashes, or when you do not want to expose sequential IDs (e.g. for security or privacy). They are ideal for REST APIs, microservices, and event logs. Integer auto-increment IDs are simpler for single-database apps; UUIDs shine when you have multiple writers or need to generate IDs offline. Storage and index size are larger than integers; for very high-throughput single-node systems, consider your database's UUID support and indexing strategy.

UUID v4 vs Other Versions

UUID v4 is random and has no embedded timestamp, so it cannot be sorted by creation time. UUID v1 includes a timestamp and node ID, so it is time-ordered but reveals hardware and time. UUID v5 (and v3) are derived from a namespace and name via hashing; same input yields the same UUID, useful for deterministic IDs. This generator produces only v4. For most applications v4 is the right choice. Collision risk is negligible (about 1 in 5.3×10³⁶ for a single pair); in practice you will never see a duplicate from a proper v4 generator.

How UUIDs Are Generated

A UUID v4 is 128 bits of random (or cryptographically random) data formatted as five groups of hex digits: 8-4-4-4-12 (e.g. 550e8400-e29b-41d4-a716-446655440000). Version 4 uses random values for most of the bits; the version nibble is set to 4 and the variant bits follow the RFC 4122 spec. Generation is typically done via the platform's secure random source (e.g. crypto.getRandomValues in the browser, crypto.randomUUID() where available). No central server is needed; each system can generate UUIDs independently and collisions are astronomically unlikely. This tool is for informational and development use only.

Limitations

This tool runs in the browser; randomness quality depends on the environment. For production systems, use your platform's built-in UUID library (e.g. crypto.randomUUID() in JavaScript, uuid module in Node.js) so that generation uses a cryptographically secure source. Do not use generated UUIDs as passwords, API keys, or secrets; they are identifiers, not credentials. Results are for informational and development use only.

Tips for Developers

In databases, store UUIDs as the native UUID type if supported (e.g. PostgreSQL, MySQL 8) for indexing and size. In APIs, use UUIDs for resource IDs when you need global uniqueness or offline ID generation. For sortability by creation time, consider UUID v7 or a time-ordered variant instead of v4. This generator does not send data to a server; IDs are created in the browser. For production, prefer your language or framework's standard UUID library. This tool is for informational use only.

When to Use This Tool

Use the UUID Generator when you need unique identifiers for development, testing, or non-security-critical IDs. Do not use generated UUIDs as secrets or tokens; use a cryptographically secure method for those. This tool is for informational use only.

How UUIDs Are Generated

This tool generates UUID v4 (random) identifiers in the browser. For production prefer your language or framework standard UUID library. This tool is for informational use only.

Disclaimer

This tool is for informational use only. Use generated UUIDs for development and non-security-critical identifiers. For secrets or tokens, use a cryptographically secure method per your platform.