GeneratorUUID

Generate universally unique identifiers (UUIDs) instantly for use in databases, APIs, session tokens, file names, and application identifiers. UUIDs (also called GUIDs) are 128-bit values formatted as 32 hexadecimal characters in groups separated by hyphens — for example, 550e8400-e29b-41d4-a716-446655440000. They are statistically guaranteed to be unique, making them ideal for distributed systems where sequential IDs would create conflicts.

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UUID Generator

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How To Use UUID Generator

  1. Open the UUID Generator tool on the page.
  2. Click the generate button to produce a new random UUID v4 value.
  3. The UUID is displayed in the standard hyphenated format (xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx).
  4. Copy the UUID using the copy button for immediate use in your code, database record, or configuration.
  5. Click generate again to produce additional UUIDs — each one is guaranteed to be unique.

Frequently Asked Questions

What is a UUID and what is it used for?

A UUID (Universally Unique Identifier) is a 128-bit number used to identify information in computer systems without requiring a central coordinator. UUIDs are used as primary keys in databases, record identifiers in distributed systems, session and authentication tokens, file names for uploaded content, API resource identifiers, and any context where a unique identifier must be assigned without coordination between systems.

What version of UUID does this tool generate?

This tool generates UUID version 4 (UUIDv4), which is created from random or pseudo-random numbers. UUIDv4 is the most widely used version for application development because it requires no external coordination, contains no identifying information about the host system, and the randomness provides extremely high uniqueness guarantees — the probability of generating two identical UUIDv4 values is astronomically small.

Is it safe to use UUIDs as primary keys in databases?

Yes, with some considerations. UUID primary keys are excellent for distributed systems, API-exposed identifiers (since they reveal nothing about record count or insertion order), and merging data from multiple databases. However, random UUIDs can cause performance issues in large indexed tables because random insertion order creates fragmented B-tree indexes. For performance-critical applications, consider UUID version 7 (time-ordered) or ULID as alternatives.

What is the difference between UUID and GUID?

UUID and GUID refer to the same concept. UUID (Universally Unique Identifier) is the standard term from the IETF RFC 4122 specification. GUID (Globally Unique Identifier) is Microsoft's terminology for the same thing, used in Windows, COM, and .NET contexts. The format and mathematical properties are identical — GUID is simply a vendor-specific name for UUID.

Can I generate UUIDs in my application without this tool?

Yes. UUID generation libraries are available for every major programming language. In JavaScript/Node.js, use the crypto.randomUUID() function (built-in) or the 'uuid' npm package. In Python, use uuid.uuid4() from the standard library. In PHP, use ramsey/uuid. In Java, use java.util.UUID.randomUUID(). This tool is for quick single-use generation and testing without writing code.

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