Generate UUIDs Online
Generate any number of UUID v4 values for test data, database seeds, API fixtures, and migration scripts. Choose your preferred format — standard, uppercase, or no hyphens.
Open UUID Generator and create UUIDs instantly.
- You are writing database seed scripts and need unique primary keys for test rows.
- You need UUIDs for fixture files in a backend test suite.
- A frontend component requires unique IDs for list rendering and you need examples for Storybook.
- You are setting up Postman environment variables and need a batch of unique IDs to test with.
- Open the UUID Generator and set the quantity (up to hundreds at a time).
- Choose the format: standard lowercase with hyphens, uppercase, or no hyphens.
- Click Generate and copy the list to your clipboard or download it as a text file.
- Use the SQL IN Clause Builder to wrap the UUIDs in a quoted IN clause for database queries.
- UUID v4 is the most portable format — avoid v1 (time-based, leaks MAC address) for general test data generation.
- When using UUIDs as database primary keys, ensure your column type is
UUIDorCHAR(36), notVARCHAR(255), to avoid index inefficiency. - The hyphen-free format (32 hex chars) is required by some systems — confirm your target system's expected format before generating in bulk.
- UUID v4 values are extremely unlikely to collide — the probability is about 1 in 10^18 for any pair.
20 UUIDs for a test fixture file
f47ac10b-58cc-4372-a567-0e02b2c3d479 3f6a2b0c-1d4e-4b7a-8c9d-2e3f4a5b6c7d 9a8b7c6d-5e4f-3a2b-1c0d-9e8f7a6b5c4d 1b2c3d4e-5f6a-7b8c-9d0e-1f2a3b4c5d6e 7c8d9e0f-1a2b-3c4d-5e6f-7a8b9c0d1e2f 2d3e4f5a-6b7c-8d9e-0f1a-2b3c4d5e6f7a 8e9f0a1b-2c3d-4e5f-6a7b-8c9d0e1f2a3b 4f5a6b7c-8d9e-0f1a-2b3c-4d5e6f7a8b9c 0a1b2c3d-4e5f-6a7b-8c9d-0e1f2a3b4c5d 6b7c8d9e-0f1a-2b3c-4d5e-6f7a8b9c0d1e c3d4e5f6-a7b8-9c0d-1e2f-3a4b5c6d7e8f 5d6e7f8a-9b0c-1d2e-3f4a-5b6c7d8e9f0a b1c2d3e4-f5a6-7b8c-9d0e-1f2a3b4c5d6e 7e8f9a0b-1c2d-3e4f-5a6b-7c8d9e0f1a2b 3f4a5b6c-7d8e-9f0a-1b2c-3d4e5f6a7b8c 9a0b1c2d-3e4f-5a6b-7c8d-9e0f1a2b3c4d f5a6b7c8-d9e0-f1a2-b3c4-d5e6f7a8b9c0 1a2b3c4d-5e6f-7a8b-9c0d-1e2f3a4b5c6d 7b8c9d0e-1f2a-3b4c-5d6e-7f8a9b0c1d2e 3c4d5e6f-7a8b-9c0d-1e2f-3a4b5c6d7e8f
UUID v4 is a randomly generated universally unique identifier (RFC 4122). It consists of 32 hex digits grouped as 8-4-4-4-12 with hyphens. Version 4 indicates random generation (unlike time-based v1 or name-based v3/v5).
Yes. The generator uses crypto.randomUUID() or crypto.getRandomValues(), which are browser CSPRNG APIs. The values are not predictable or reproducible.
GUID is Microsoft's name for the same concept. A UUID v4 is functionally identical to a GUID v4 and is accepted by all Windows and .NET APIs that expect a GUID.
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