UUID Generator
Generate up to 1,000 UUIDs at once, as random version 4 or sortable version 7, ready to paste into code, a database seed, or test fixtures.
Overview
UUIDs give you a unique identifier without needing a central counter or database round-trip. Version 4 UUIDs are built entirely from random bits, so any two generated independently are, for practical purposes, guaranteed not to collide. That makes them a common choice for request IDs and test data where uniqueness matters but ordering doesn't.
Version 7 UUIDs, standardized in RFC 9562, start with a Unix millisecond timestamp followed by random bits. They're just as unique, but they sort in the order they were created. As database primary keys, that keeps new rows appending to the end of the index instead of landing at random positions, which avoids the page splits and bloat that random v4 keys cause on large tables.
Examples & Sample Data
Version 4 (random)
Version: v4 Count: 1
3f29c1de-8a4b-4e3a-9c2d-1a2b3c4d5e6f
Version 7 (time-ordered) — note the shared timestamp prefix
Version: v7 Count: 3
0192f3a4-7b1c-7d2e-9f30-4a5b6c7d8e9f 0192f3a4-7b1c-7d2f-b1a2-93c4d5e6f708 0192f3a4-7b1c-7d30-8e4f-1a2b3c4d5e6f
How It Works
- Choose v4 for fully random UUIDs, or v7 for UUIDs that sort by creation time.
- Enter how many you need, up to 1,000.
- Pick a format: with or without hyphens, uppercase, or wrapped in braces.
- Click Generate, then copy the list or download it as a text file.
- To examine an existing UUID, paste it into Inspect a UUID to see its version, variant, and any embedded timestamp.
Frequently Asked Questions
No. UUIDs are generated entirely in your browser using the Web Crypto API's cryptographically secure random number generator.
Version 4 UUIDs are randomly generated with enough entropy that collisions are astronomically unlikely, though not mathematically impossible.
Up to 1,000 per click. Use Download to save a large batch as a text file.
Yes. Prefer v7 for primary keys: its timestamp prefix keeps inserts in index order, which random v4 keys don't. Either way, UUIDs are larger than integer IDs, and a v7 UUID reveals roughly when the row was created.
A v4 UUID is 122 random bits. A v7 UUID starts with a 48-bit Unix millisecond timestamp and fills the rest with random bits, so v7 UUIDs sort by creation time. UUIDs generated in the same batch here still sort in the order they were made.
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