UUID Generator
Generate unique identifiers (UUIDs) in v1 or v4 format
Generated UUIDs will appear here...
UUID Versions
- v4: Random UUID - Most commonly used, no dependencies
- v1: Time-based UUID - Includes timestamp and MAC address
About UUID Generator
Generate RFC 4122 version 4 UUIDs individually or in bulk, with optional uppercase and brace formatting.
How to use UUID Generator
- Set how many identifiers you need.
- Choose formatting options if a system expects them.
- Copy the list into your fixtures, seed script or database.
Common use cases
- Creating primary keys for seed data.
- Labelling test objects without collisions.
- Generating correlation IDs for request tracing.
Common questions
Are these UUIDs random?
Yes. Version 4 UUIDs are generated from random bits (with the version and variant bits fixed), so collisions are negligible.
Should UUIDs be used as database keys?
They are convenient for distributed systems, but random UUIDs fragment B-tree indexes. Many teams use UUIDv7 or a sequential primary key with a UUID column.
Are uppercase UUIDs valid?
Yes. UUIDs are case-insensitive in practice; pick one format and stay consistent within a system.
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