UUID generator

Generate secure random UUID v4 identifiers, one or in bulk — instantly and privately.

Random UUIDs whenever you need them

A UUID (universally unique identifier) is a 128-bit value used as a collision-free key for database rows, API requests, files and distributed systems. This generator creates version 4UUIDs using your browser's secure random source, so they are suitable for production use — and you can produce up to 100 at once.

Toggle uppercase if your system expects it, then copy the whole batch with a single click. Everything is generated locally; nothing is uploaded.

How to generate UUIDs

Set how many identifiers you need (1 to 100), flip the uppercase switch if required, and click Generate. The whole list appears at once and copies with a single button, ready to paste into a seed script, a test fixture, an API request or a spreadsheet. Generate another batch any time you need fresh values — each one is drawn from a secure random source.

Where v4 UUIDs are used

Teams use random UUIDs as database keys, request and trace IDs for debugging, idempotency keys, file names and message identifiers in queues. If you also need one-way fingerprints or random secrets, pair this with the hash generator and password generator. The complete toolkit is on the developer tools page.

Frequently asked questions

What kind of UUID does this generate?
Version 4 (random) UUIDs, created with the browser's cryptographically secure crypto.randomUUID(). Each one is a 128-bit identifier in the standard 8-4-4-4-12 format.
Can I generate many UUIDs at once?
Yes. Set any count from 1 to 100 and generate them all instantly, then copy the whole list with one click.
Are the UUIDs unique?
Version 4 UUIDs are random with 122 bits of entropy, so the chance of a collision is astronomically small — they are safe to use as database keys, request IDs and file names.
Is this private?
Yes. UUIDs are generated locally in your browser using a secure random source; nothing is sent to a server.
What is the difference between UUID v1 and v4?
Version 1 UUIDs are built from a timestamp and the machine's MAC address, so they leak some metadata and ordering. Version 4 UUIDs are fully random, which makes them unpredictable and the safest default for most applications — and that is what this tool generates.
Can I really use these as database primary keys?
Yes. Random v4 UUIDs are widely used as primary keys because they can be generated anywhere without coordination, avoiding the collisions you risk with auto-incrementing IDs across distributed services. Just index them appropriately for performance.
What does the uppercase toggle do?
It switches the hex digits between lowercase (the canonical form) and uppercase. Some legacy systems and databases expect uppercase UUIDs, so the toggle lets you match whatever format your target requires.
How unlikely is a collision, really?
A v4 UUID has 122 random bits. You would need to generate billions of UUIDs before the probability of a single collision became meaningful, which is why they are treated as practically unique without a central authority.

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By Narender Chaudhary, Editorial & Product Lead · Updated June 2026

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