UUID generator and GUID generator online

What is a UUID?

A UUID (Universally Unique Identifier), also called a GUID, is a 128-bit value written as 36 characters such as 550e8400-e29b-41d4-a716-446655440000. UUIDs let independent systems create identifiers — for database rows, files or events — without a central authority, with a vanishingly small chance of collision.

How to generate a UUID

1. 1 Choose a version: v4 (random), v7 (time-ordered), v1, v3/v5 (name-based) or NIL.
2. 2 Set how many to generate and pick format options like uppercase, braces or URN.
3. 3 Click Generate, then copy the list or download it as a file.
4. 4 Paste an existing UUID into the validator to check it and detect its version.

UUID notes and pitfalls

• Random is not sequentialv4 is fully random, which scatters database indexes. Use v7 when you need time-ordered, index-friendly ids.
• v1 can leak informationVersion 1 embeds a timestamp and node identifier. Prefer v4 or v7 if that metadata is sensitive.
• Case and formattingUUIDs are case-insensitive but usually lowercase. Braces and the urn:uuid: prefix are optional styles.

UUID and GUID generator code

crypto.randomUUID()

uuid.uuid4()

UUID.randomUUID()

Guid.NewGuid()

[guid]::NewGuid()

uuidgen

uuidv7()  --  gen_random_uuid() for v4

NEWID()

import { v4, v7 } from "uuid"