UUID/GUID v4 Generator
Generate random UUID v4 strings instantly — cryptographically secure unique identifiers for databases, APIs, and testing. Free and client-side.
🔒 100% Client-Side Processing
Your data is processed entirely in your browser and never transmitted to any server.
Common Use Cases
Creating database record IDs
Generate primary keys for rows you're inserting manually during development, seeding, or data repair.
Writing API test fixtures
Fill request bodies, mock responses, and test data with valid v4 UUIDs where endpoints demand proper identifiers.
Assigning correlation IDs
Create unique trace identifiers to tag a request through logs across distributed services while debugging.
Frequently Asked Questions
- How random and unique is a UUID v4?
- It contains 122 random bits from crypto.randomUUID(), a cryptographically secure source. Collisions are so improbable (billions generated for centuries) that v4 UUIDs are safely treated as globally unique database and API identifiers.
- What do the digits in a v4 UUID mean?
- The format is 8-4-4-4-12 hex digits. The third group always starts with 4 (the version) and the fourth starts with 8, 9, a, or b (the variant); everything else is random. If you need timestamp-ordered IDs, see the UUID v1 tool.
- Is my data private when I use this tool?
- Yes. This tool runs entirely in your browser using client-side JavaScript — nothing you type is transmitted to, logged by, or stored on any server. You can safely process confidential text, tokens, or code.