UUID / NanoID Generator
Generate UUID v4/v7 or short NanoID strings in bulk.
Click Generate to create IDs
About the UUID / NanoID Generator
Generate RFC 4122 compliant UUIDs and compact NanoIDs in bulk. A UUID is a 128-bit identifier that is unique without any coordination between machines, which is why it is the default choice for primary keys in distributed systems, idempotency keys, and correlation IDs across microservices.
How to use it
- 1 Pick the format you need: UUID v4 for pure randomness, UUID v7 for time-ordered IDs, or NanoID for short URL-friendly strings.
- 2 Set how many identifiers you want to generate at once.
- 3 Click Generate — a fresh batch appears immediately.
- 4 Copy a single value, or copy the whole list for seeding a database.
What it does
- UUID v4 — 122 bits of cryptographic randomness
- UUID v7 — time-sortable, ideal for database primary keys
- NanoID — shorter and URL-safe, with configurable length
- Bulk generation with one-click copy of the full list
- Uses the crypto secure random source, not Math.random()
Frequently asked questions
Are the generated IDs sent anywhere?
No. Every calculation happens locally in your browser using JavaScript. Nothing you paste is uploaded, logged, or stored on a server, which makes the tool safe to use with production data, credentials, and customer records.
What is the difference between UUID v4 and UUID v7?
v4 is entirely random, so consecutive IDs land in unrelated places in a database index and cause page splits on insert. v7 puts a millisecond timestamp in the high bits, so IDs sort chronologically and insert sequentially. For a new table primary key, v7 is usually the better choice; for tokens that must not leak creation time, use v4.
Can two UUIDs ever collide?
In theory yes, in practice no. A v4 UUID has 122 random bits. You would need to generate roughly 2.7 quintillion of them before reaching a one-in-a-billion chance of a single duplicate. Collision is not a risk worth engineering around.
When should I use NanoID instead of a UUID?
When the ID appears in a URL or has to be typed or shared. A NanoID is 21 characters versus a UUID's 36, uses a URL-safe alphabet with no hyphens, and offers comparable collision resistance. Use a UUID when a library, database column type, or specification requires the standard format.
Are these UUIDs cryptographically secure?
Yes. They are generated with crypto.getRandomValues(), the browser's cryptographically secure random number generator, not the predictable Math.random(). The values are safe to use where unguessability matters.