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Toova
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UUID Generator (v1, v4, v7, NIL)

Private by design — runs entirely in your browser

Generate UUIDs of every common version — v1, v4, v7, and the nil UUID — in your browser. Toova creates one at a time or in bulk, copies with one click, and never sends a request to any server while generating.

Which UUID version to use

UUID v4 is random and is the most common pick when you just need a unique identifier with no ordering. UUID v7 is time-ordered, which makes it ideal for database primary keys because inserts land at the end of the index instead of scattering through it. UUID v1 is timestamp-and-MAC based and is rarely the right choice today. Toova generates all three, plus the nil UUID for testing.

Bulk generation and formatting

Generate a single UUID for quick testing, or up to ten thousand at a time for seeding fixtures, populating dev databases, or load testing. Output formats include the canonical hyphenated form, hex without hyphens, uppercase, and braces-wrapped for languages that expect that style. The result is copyable with one click and can be exported as a plain text list.

Cryptographically random, locally

Random UUIDs use the browser's cryptographic random number generator, the same source your browser uses for TLS keys. The values are unpredictable and unique with overwhelming probability. Generation runs entirely in your browser — no server is involved, no logging happens, and you can verify zero outbound requests with the Network tab open.

Frequently Asked Questions

Should I use v4 or v7 for my database?
Use v7 for new database designs. Time-ordered IDs cluster recent inserts in the same index page, which dramatically improves write performance and locality. Stick with v4 if your system already relies on unpredictable random IDs.
How unique are random UUIDs?
UUID v4 has 122 bits of randomness, which means the probability of a collision is vanishingly small for any reasonable application. You would need to generate trillions before the risk became material.
Can I generate UUIDs in bulk?
Yes. Toova can produce up to ten thousand at a time. The output is one UUID per line, ready to paste into a database seeder or a fixture file.
What is the nil UUID?
The nil UUID is 00000000-0000-0000-0000-000000000000. It is used as a sentinel value to mean "no UUID assigned" or as the test placeholder in code samples.
Is the generation truly random?
Yes. Toova uses the browser's cryptographic random number generator — the same source used for TLS keys and secure cookies. No predictable seeds are involved.