What Is This Tool?
A UUID (Universally Unique Identifier) is a 128-bit identifier written as 36 characters, like 550e8400-e29b-41d4-a716-446655440000. Version 4 UUIDs are generated from random data, which makes collisions so unlikely they can be ignored in practice: you could generate a billion UUIDs per second for decades before a duplicate becomes probable.
UUIDs are used as database primary keys, request IDs for tracing, filenames, API keys, and anywhere you need an identifier without coordinating with a central authority.
Why Use It?
- Cryptographically secure: uses crypto.randomUUID(), not weak Math.random().
- Bulk generation — up to 500 UUIDs at once, one per line, ready to paste.
- Uppercase and no-hyphen options for systems with specific format requirements.
- Runs offline in your browser; the UUIDs are never sent anywhere.
- Free and instant, no login.
How to Use
- Choose how many UUIDs you need (1–500).
- Optionally check "Uppercase" or "Remove hyphens".
- Click "Generate UUIDs".
- Click "Copy All" to copy the whole list.
Example
Input
Count: 3Output
f47ac10b-58cc-4372-a567-0e02b2c3d479
9c858901-8a57-4791-81fe-4c455b099bc9
16fd2706-8baf-433b-82eb-8c7fada847daEach UUID is generated independently from secure random data.
Frequently Asked Questions
Can two generated UUIDs collide?
Theoretically yes, practically no. A v4 UUID has 122 random bits. The probability of a collision stays negligible even after generating trillions of them — it's safe to treat them as unique.
What's the difference between UUID versions?
v1 is based on timestamp + MAC address (leaks information), v4 is fully random (the most common choice), v5 is derived from a name via hashing (deterministic), and v7 is time-ordered random (good for database indexes). This tool generates v4.
Are these UUIDs secure enough for tokens?
They use a cryptographically secure random source, which is much better than Math.random(). For session tokens, dedicated token generators with more entropy are still preferred, but v4 UUIDs are fine for identifiers.
Is UUID the same as GUID?
Yes. GUID (Globally Unique Identifier) is Microsoft's name for the same 128-bit format. The terms are interchangeable.
Are the generated UUIDs stored or logged?
No. Generation happens locally in your browser. Nothing is transmitted, stored or logged — every UUID you see exists only on your screen.