Practical usage guide
What this tool does
UUID Generator creates version 4 UUIDs with the browser Web Crypto API. A v4 UUID contains random bits plus fixed version and variant bits, producing identifiers such as 550e8400-e29b-41d4-a716-446655440000 without contacting a server.
UUIDs are useful when many clients need to create identifiers independently. Their large space makes accidental collisions extremely unlikely, but application constraints and database indexes still matter.
Quick start
Choose a batch size
Generate only the number you need for test records, fixtures, or local identifiers. The engine supports up to 100 values per run.
Choose display case
Uppercase and lowercase UUID text represent the same hexadecimal value. Follow the convention used by your database or API.
Store with an appropriate type or constraint
Use a native UUID type when available and keep a unique constraint for application-level integrity.
Common use cases
Create development fixtures
Generate identifiers for sample records without depending on a backend endpoint.
Assign client-side identifiers
Create temporary or offline IDs that can later be synchronized with a service.
Prepare correlation IDs
Generate values for local testing of request, event, or trace correlation fields.
Limitations and important notes
Only UUID v4 is generated
The tool does not create time-ordered UUID v1, v6, v7, namespace-based UUID v5, ULID, or database-specific sequential IDs.
Randomness does not replace uniqueness constraints
Collision probability is tiny, not mathematically zero. Keep database or application safeguards where duplicate IDs would be harmful.
UUIDs are identifiers, not secrets
Do not use a UUID alone as an access token or authorization control. Treat publicly exposed IDs as discoverable.