The UUID / NanoID generator produces unique identifiers on demand: classic random UUID v4, the newer time-ordered UUID v7, or a compact 21-character NanoID. Choose a type, pick how many you need, and get a clean list you can drop straight into a database seed, a test fixture or an API call.
Every id is generated locally in your browser using the platform crypto RNG (crypto.randomUUID and crypto.getRandomValues). Nothing is requested from a server and nothing you generate is uploaded, logged or stored — the ids exist only in your tab, which makes them safe to use for real records.
It is built for developers who need identifiers fast: primary keys, correlation ids, idempotency keys, file names or trace ids. Switch the output to a JSON array to paste a batch directly into code, or keep the one-per-line list for a quick copy. Free forever, no signup, no limit.
Version 4 is 122 bits of cryptographic randomness with the version and variant bits fixed. It is the universal default: no coordination, effectively zero collision risk, and supported everywhere. The tool uses the browser's native crypto.randomUUID when available and a crypto.getRandomValues fallback otherwise.
Version 7 (RFC 9562) puts a 48-bit Unix-millisecond timestamp at the front, then version and variant bits, then randomness. Because the leading bits increase over time, v7 ids sort chronologically — far friendlier to database B-tree indexes than the random scatter of v4.
NanoID is a 21-character id drawn from a 64-symbol URL-safe alphabet (A-Z, a-z, 0-9, plus _ and -). It is shorter than a UUID, needs no hyphens, and is safe to drop into URLs or file names. The alphabet divides 256 evenly, so each character is unbiased.
Generate 1, 10 or 50 ids at a time. Leave the JSON toggle off for a plain one-per-line list you can copy, or turn it on to wrap the batch in a formatted JSON array ready to paste into a config, a seed script or a test.
v4 is fully random, so ids are unordered — great for privacy and simplicity. v7 embeds a millisecond timestamp at the start, so ids are time-sortable and index more efficiently in databases. Use v4 for general uniqueness and v7 when insertion order or index locality matters.
Neither is strictly better — it is a trade-off. NanoID is shorter (21 chars vs 36) and URL-safe without hyphens, which is nice for links and file names. UUID is a formal standard recognised by databases and libraries. For public identifiers NanoID is often more compact; for interop UUID is safer.
Yes. They are generated locally with your browser's cryptographic RNG (crypto.getRandomValues / crypto.randomUUID), the same source used for secure tokens. Nothing is uploaded, so the ids you see are yours alone and safe for production records.
In practice, no. A v4 UUID has 122 random bits — you would need to generate billions of ids per second for many years to have a meaningful chance of a single collision. v7 keeps the same random tail plus a timestamp, so its collision odds are just as negligible.
Completely. There is no account, no limit and no upload — every id is produced in your browser and never sent anywhere. You can disconnect from the internet and it still works.