7ae287bf-77da-45c8-ad9d-bc74b12b236e
Common Problems
How to generate a UUID online?
UUID v4 generates 128-bit identifiers using cryptographically secure random numbers, giving a collision probability of 1 in 5.3×10³⁶ per pair.
How to create a GUID for a database primary key?
Generating primary keys for SQL and NoSQL database records. They use window.crypto.randomUUID() — the browser's CSPRNG, the same source used for TLS and cryptographic key generation. Creating idempotency keys for API requests to prevent duplicate processing.
How to generate multiple UUIDs at once?
This tool generates single or bulk UUIDs instantly using your browser's built-in crypto API.
How to create a random unique ID?
For most use cases yes — v4 is purely random and doesn't leak machine info or timestamp. Use v1 only when sortable time-ordering is required.
Difference between UUID v1 and UUID v4?
They use window.crypto.randomUUID() — the browser's CSPRNG, the same source used for TLS and cryptographic key generation.
Workflow
What is UUID Generator?
UUID v4 generates 128-bit identifiers using cryptographically secure random numbers, giving a collision probability of 1 in 5.3×10³⁶ per pair. This tool generates single or bulk UUIDs instantly using your browser's built-in crypto API.
How to use UUID Generator
Click Generate for a single UUID, or set a quantity (up to 100) and click Bulk Generate. Copy individual UUIDs or all at once. The Recent History panel keeps your last 10 generated IDs.
Example
Single: f47ac10b-58cc-4372-a567-0e02b2c3d479
Bulk (3):
3d721da8-8e4b-4f1a-b2e9-c1d3f5a7e291
9b2c4e6f-1a3b-5c7d-8e9f-0a1b2c3d4e5f
1a2b3c4d-5e6f-7a8b-9c0d-1e2f3a4b5c6dUse Cases
1. Generating primary keys for SQL and NoSQL database records.
2. Creating idempotency keys for API requests to prevent duplicate processing.
3. Unique filenames for user-uploaded assets in object storage.
4. Session IDs and correlation IDs for distributed system tracing.
5. Generating test fixtures with unique identifiers.
FAQ
How random are these UUIDs?
They use window.crypto.randomUUID() — the browser's CSPRNG, the same source used for TLS and cryptographic key generation.
Is UUID v4 better than UUID v1?
For most use cases yes — v4 is purely random and doesn't leak machine info or timestamp. Use v1 only when sortable time-ordering is required.
Can two generated UUIDs ever be equal?
Theoretically yes, but the probability is about 1 in 10³⁶. In practice, you will never encounter a collision.