UUID generation workflow
Generate UUIDs for database keys and API IDs
UUIDs give every record a unique identifier without a central counter. The UUID generator creates version 4 UUIDs locally, in bulk, and in the exact format your code expects.
The fast workflow
Follow the same short workflow every time so the result is predictable.
Pick the format
Choose hyphenated or plain, and uppercase or lowercase output.
Choose the count
Generate one UUID or a batch for test data and migrations.
Copy the list
Copy the results as a list or comma-separated values.
Use in your code
Insert them as primary keys, API IDs, or idempotency keys.
When UUIDs beat auto-increment IDs
Auto-increment IDs are simple but predictable: they leak how many records exist and collide when systems merge. UUIDs are unique across databases, which makes offline and distributed inserts safe.
For idempotency keys in APIs, generate one UUID per request so retries cannot create duplicate operations.
Common problems
- Using sequential IDs that leak record counts
- Hand-writing UUIDs, which risks duplicates
- Using UUIDs without checking your database column type
Best practices
- Use UUIDs as opaque identifiers, not as sort keys
- Store them as UUID or CHAR(36) columns, not INT
- Keep v4 for random needs; use v7 only if your tooling supports it
Frequently asked questions
What is a version 4 UUID?
Version 4 UUIDs are generated from random bytes with version and variant bits set. Collisions are astronomically unlikely.
Can I generate many UUIDs at once?
Yes. The generator produces batches in one click, which is handy for test fixtures and migrations.
Are UUIDs secure enough for tokens?
UUIDs are unique, but they are not designed as secrets. For tokens, use a dedicated generator with high-entropy output.
Does the generator need a server?
No. UUIDs are created locally with the browser crypto API.
Your data stays local
Everything runs in your browser. Files and values are never uploaded or stored.
Open UUID Generator