UUID Generator
1–1000 · one per line when more than one
A UUID (Universally Unique Identifier) is a 128-bit value, conventionally written as 32 hexadecimal digits split into five groups — 3fa85f64-5717-4562-b3fc-2c963f66afa6, for example. Version 4, the variant this tool generates, is the most common one in practice: aside from a handful of fixed bits that mark the version, every bit is random. With 122 bits of randomness, generating a UUID and expecting it to already exist somewhere else is not a realistic concern.
Each ID comes from crypto.randomUUID(), a native browser method built specifically for this — there’s no manual assembly of random bytes into the UUID format happening in this tool’s own code, which removes a whole category of off-by-one or formatting bugs that hand-rolled implementations are prone to.
One UUID is generated the moment the page loads. To get more than one, raise the “How many” field above 1 — up to 1,000 per batch — and each is placed on its own line in the output. A large batch is exactly the situation where the Download button is most useful, saving the full list to a .txt file rather than requiring a copy-paste of a thousand lines. As with the rest of the output, generation happens entirely in the browser tab; nothing about the request or the resulting IDs is sent anywhere.
Examples
- Generating a primary key for a database row when the schema uses UUIDs instead of auto-incrementing integers.
- Creating a unique filename for a user-uploaded file, so two people uploading photo.jpg on the same day never collide.
- Seeding a batch of placeholder IDs for test fixtures or a mock API response, without wiring up a real ID-generation service.
Frequently asked questions
Are the UUIDs sent to a server?
How likely is a collision between two generated UUIDs?
What is the maximum batch size?
.txt file, one UUID per line.