UUID Generator
Generate UUID v4 or time-ordered UUID v7 identifiers in bulk. Choose the output format, casing, hyphens, and braces, then copy or download the results — all in your browser.
Last updated September 6, 2026
How to Generate UUIDs
Create one UUID or a full batch in a few steps:
- Choose UUID v4 for random identifiers or UUID v7 for time-ordered identifiers.
- Enter how many UUIDs you need.
- Choose casing, hyphens, braces, and the output format.
- Click Generate to create a new batch.
- Copy one UUID, copy the full batch, or download the results.
UUIDs are generated directly in your browser using a cryptographically secure random source.
What Is a UUID?
A UUID (Universally Unique Identifier) is a 128-bit identifier used for records, resources, events, request IDs, and distributed systems without requiring a central authority to allocate each ID.
UUIDs are identifiers, not secrets. Do not use a UUID alone as a password, API key, session secret, or security token.
UUID v4 vs. UUID v7
UUID v4 remains a strong general-purpose default. UUID v7 is useful when identifiers should sort roughly by creation time, which can improve index locality compared with fully random keys. Do not assume v7 is always better for every database.
| Version | How it is built | Best fit |
|---|---|---|
| UUID v4 | Random bits | General identifiers where ordering is not needed |
| UUID v7 | Timestamp + random bits | Database keys, event IDs, logs, and data that benefits from chronological sorting |
What Does a UUID Look Like?
A UUID contains 128 bits and is commonly displayed as 32 hexadecimal characters in an 8-4-4-4-12 pattern:
550e8400-e29b-41d4-a716-446655440000
The hyphens and letter casing are formatting choices. Removing hyphens or using uppercase changes the text representation, not the underlying 128-bit identifier.
Generate UUIDs in Code
These are UUID v4 examples unless the API or library shown supports v7.
JavaScript (v4): crypto.randomUUID() Python (v4): import uuid; str(uuid.uuid4()) PostgreSQL (v4): SELECT gen_random_uuid(); Shell (platform-dependent): uuidgen
UUID v7 support varies by language version and library. Use a maintained library that explicitly implements RFC 9562 rather than assuming a built-in v7 API exists.
Frequently asked questions
What is a UUID?
A UUID is a 128-bit identifier designed so different systems can create IDs independently with an extremely low risk of collision.
What is the difference between UUID v4 and v7?
UUID v4 is random. UUID v7 includes a timestamp component, so values sort by creation time while retaining random bits for uniqueness.
Are UUID v4 values guaranteed to be unique?
No finite random identifier can be mathematically guaranteed unique, but properly generated v4 UUID collisions are extraordinarily unlikely.
Can I use UUIDs as database primary keys?
Yes. v4 is common, while v7 can be attractive for large indexed tables because time-ordered values usually have better index locality.
Are UUIDs secure secrets?
No. UUIDs are identifiers. Do not rely on them alone as passwords, API keys, session secrets, or authentication tokens.
Can I generate UUIDs in bulk?
Yes. Choose the quantity and generate the whole batch at once.
Are generated UUIDs sent to Utillery?
No. Generation runs locally in your browser.