UUID, ULID and NanoID Generator

Features

• Four types: UUID v4, UUID v7, ULID and NanoID
• Generate 1 to 1000 values at a time, one per line for easy column copying
• UUID v4 writes the version and variant bits exactly as RFC 4122 requires, so any validator accepts it
• UUID v7 and ULID share one millisecond timestamp per batch with an incrementing counter, so sorting the batch equals generation order
• ULID uses Crockford Base32, which leaves out the easily confused I, L, O and U
• Switch to uppercase hex, or drop the hyphens entirely

How to use

1. Pick the type: v4, v7, ULID or NanoID
2. Set the count, up to 1000
3. Tick uppercase or hyphens if you need them
4. Leave the input box empty and click Run
5. Click Copy to take the whole column

FAQ

Can I use a UUID as a password or an API key?

No. A UUID is an identifier, not a secret: it is designed to appear in URLs, logs, primary keys and query strings, so it cannot be kept confidential. The time-ordered variants leak their creation time on top of that. For something unguessable use the password generator with a length of 16 or more; for a real key, use a dedicated key management system rather than hand-rolling one.

v4 or v7 for a database primary key?

Use v7. Because it is time-ordered, new rows always append near the end of the index, so writes stay sequential. Random v4 keys keep splitting index pages, and the difference shows up quickly as a table grows. Go with v4 when you specifically do not want outsiders to infer when a record was created.

Is a batch of v7 values sorted?

Yes. Every v7 in one run shares the same millisecond timestamp and increments the 12-bit rand_a counter, so sorting the copied column reproduces the generation order exactly. That guarantee is per run; a second click starts a fresh batch.

Is anything uploaded or logged?

No. Randomness comes from the browser built-in crypto.getRandomValues, generation happens in memory on your machine, and the page makes no network requests. It works offline.