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UUID Generator

Generate UUID v4, time-sortable UUID v7, and Nano IDs in bulk.

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About this tool

Generate cryptographically random UUID v4, time-sortable UUID v7 (RFC 9562 draft), and Nano IDs in bulk (up to 1000 at once). Toggle hyphens, uppercase, and Nano ID length. Copy individually or all, or download as a .txt file.

Why generate UUIDs in your browser?

Universally Unique Identifiers are the most common way to give a database row, a session, or an event a guaranteed-unique identifier without coordinating with a central authority. They are widely supported, easy to copy and paste, and short enough to fit comfortably in a URL or log line. Most developers reach for an online generator dozens of times a year: while seeding a test database, while writing API documentation, while building a quick demo.

Versions on offer

  • UUID v4 — cryptographically random. The most common variant. Use whenever you do not need temporal ordering.
  • UUID v7 — RFC 9562 draft. The first 48 bits encode the Unix millisecond timestamp; the remainder is random. Sorts naturally by creation time, which makes it ideal as a database primary key.
  • Nano ID — a smaller alternative (21 characters by default) using a URL-safe alphabet. Great for short URLs and resource IDs that need to fit in tight UIs.

How randomness is guaranteed

All identifiers are generated using the browser native crypto.getRandomValues and crypto.randomUUID APIs. These functions read from the same cryptographically secure random source used for TLS, password hashing, and key generation — so the probability of collision is effectively zero. There is no upload, no logging, and no server. Generate one, generate a thousand, refresh and generate a thousand more.

Frequently asked questions

What is UUID v7?

UUID v7 is a time-sortable UUID variant defined in RFC 9562. The first 48 bits encode the Unix millisecond timestamp, the remaining bits are random. This makes UUID v7 ideal as a database primary key — globally unique like v4, but sortable by creation time.

Is the randomness secure?

Yes. All IDs are generated using the browser native crypto.getRandomValues and crypto.randomUUID APIs — the same cryptographically secure random source used for TLS keys and password hashing.

How do I generate a UUID online?

Open the generator, click Generate, and copy the result. Click again for a fresh UUID. Use the bulk option to generate up to 1000 at once.

What is the difference between UUID v4 and UUID v7?

UUID v4 is fully random. UUID v7 embeds a millisecond timestamp at the front, making it sortable. Pick v4 when you do not need temporal ordering; pick v7 when using the UUID as a database primary key.

How many UUIDs can I generate at once?

Up to 1,000 in a single batch. Download as a .txt file or copy all to clipboard.

What is a Nano ID?

Nano ID is a smaller alternative to UUID (21 characters by default) that uses a URL-safe alphabet. It is ideal for short URLs and resource identifiers where the full 36-character UUID is too long.

Are the generated UUIDs unique?

The probability of UUID v4 collision is approximately 1 in 2^122. Practically: even generating a billion UUIDs per second for a hundred years, the chance of a duplicate is negligible.