Guide
Generate UUID online
UUID version 4 identifiers are random 128-bit values used as database keys, correlation IDs, and test fixtures. Generate one or a batch in the browser—RFC 4122 layout, no signup, copy in one click.
UUID v4 use cases
Primary keys in distributed systems, request tracing, upload file names, and seeding integration tests. Prefer UUIDs when auto-increment integers leak information or collide across shards.
Bulk generation tips
Use bulk mode for fixture files—paste into SQL COPY, JSON arrays, or CSV importers. Store mappings if tests need stable references across runs.
Not a security token
UUIDs are unique, not secret. For session tokens or password reset links, use cryptographically secure random bytes with proper entropy and expiry.
FAQ
Are UUID v4 values guaranteed unique?
Collision probability is negligible for practical apps. Still index your database column and handle rare conflicts in high-volume systems.
UUID v4 vs ULID?
ULIDs are time-sortable; UUID v4 is random. Choose ULID when chronological clustering helps indexes.
Can I generate UUID v7 here?
This tool focuses on v4. For time-ordered IDs, use a library that implements UUID v7 in your stack.
Does generation use a server?
No—random bytes are created locally via Web Crypto APIs in supported browsers.