Press Generate to create UUIDs.
A one-click tool for generating UUIDs (universally unique identifiers) in bulk. It's handy whenever you just need a unique ID — database primary keys, API request IDs, file names or tokens, or seeding test data. Pick the version: `v4` (fully random) or `v7` (the first 48 bits are a Unix-millisecond timestamp, so IDs sort in time order — increasingly popular as a database primary key). Set how many to make (1–500) to produce a whole batch at once, and use "Copy all" to grab the newline-separated list. Toggle "Uppercase" for upper-case hex, or turn off "Hyphens" to output the 32-character form without dashes. Your choices are remembered in your browser so it opens the same way next time. Random bytes come from the browser's cryptographic generator `crypto.getRandomValues`, which is safer and more collision-resistant than `Math.random`. Importantly, neither the generated UUIDs nor your settings are ever uploaded, stored, or sent to a server — all computation happens entirely inside your browser, so it's safe to use alongside internal system IDs or sensitive data. With v7, IDs created in the same millisecond share the timestamp portion but the rest is random, so every ID in a batch is still unique.
How to use
- Choose the version (v4 random / v7 time-ordered) and how many to generate.
- Press "Generate" to list that many UUIDs (toggle uppercase and hyphens as you like).
- Grab them with the per-row "Copy" or "Copy all". Generated values are never sent anywhere.
FAQ
Are the generated UUIDs uploaded anywhere?
No. Generation runs entirely in your browser with JavaScript / crypto.getRandomValues. Neither the UUIDs nor your settings are uploaded, stored, or sent to a server, so it's safe to use for internal IDs or sensitive purposes.
What's the difference between v4 and v7?
v4 is a fully random UUID. v7 puts the generation time (Unix milliseconds) in the first 48 bits with the rest random, so sorting the strings orders them by creation time. That improves index locality, which is why v7 is increasingly chosen as a database primary key.
Is the randomness good enough?
Yes. It uses the browser's cryptographic random generator, crypto.getRandomValues. Unlike Math.random, this is cryptographically secure randomness, more than sufficient for unique UUIDs.
Can I output without hyphens or in uppercase?
Yes. Turn off "Hyphens" for the 32-character form without dashes, and enable "Uppercase" for upper-case hex. These choices are saved in your browser and restored next time.
Will a batch ever produce duplicates?
In practice, no. v4 has 122 random bits and v7 combines time with randomness, making collisions negligibly unlikely by design. Even multiple v7 IDs made in the same millisecond differ, because everything after the timestamp is random.