UUID Generator
Generate version 4 UUIDs instantly. Create one or a batch of up to 100, then copy them all with a single click.
Need unique IDs for database rows, request tracing, or test fixtures? This generator produces RFC 4122 version-4 UUIDs using your browser's cryptographically secure random number generator. Generate a single ID or a batch of up to 100 and copy the whole list at once.
Version 4 UUIDs are 128-bit random identifiers (RFC 4122) — safe for database keys, request IDs, and anywhere you need a practically unique token.
How to use this calculator
- Choose how many UUIDs you need (1–100).
- Click Generate.
- Use Copy all to grab the newline-separated list.
Worked example
A typical version-4 UUID looks like 550e8400-e29b-41d4-a716-446655440000 — 32 hex digits in the 8-4-4-4-12 pattern, with the "4" in the third group marking the version and the "a" marking the RFC 4122 variant.
Frequently Asked Questions
What is a UUID?
A Universally Unique Identifier is a 128-bit value written as 32 hex digits in five groups (8-4-4-4-12), like 550e8400-e29b-41d4-a716-446655440000. They're designed so independently generated IDs practically never collide, which makes them ideal for distributed systems where no central authority hands out IDs.
What does version 4 mean?
The version nibble — the first digit of the third group — records how the UUID was made. Version 4 means fully random: 122 bits of randomness. Other versions derive from timestamps (v1), names (v3/v5), or are time-sortable (v7). v4 is the right default when you just need a unique random ID.
Are these UUIDs cryptographically random?
Yes. They're generated with crypto.randomUUID(), which draws from your operating system's cryptographically secure random number generator. They're suitable for session IDs and non-secret tokens. For actual secrets like API keys, prefer a longer dedicated token from the random string generator.
Can two UUIDs collide?
In practice, no. With 122 random bits you'd need to generate around 2.7 quintillion UUIDs to reach even a 50% collision chance. You will run out of disk space, budget, and patience long before a collision becomes a realistic concern.
Why generate a batch instead of one at a time?
When seeding a database, writing tests, or building fixtures you often need dozens of unique IDs at once. Batch mode generates up to 100 in one click and the Copy all button gives you a newline-separated list ready to paste into a script or spreadsheet.