ToolNestFree Online UUID Generator
Need unique identifiers for your database, API, or test fixtures? Our free UUID generator creates cryptographically random UUID v4 values and time-ordered UUID v7 values in bulk — up to 500 at once — using your browser's secure random number generator. Nothing is sent to any server.
✓ Free forever · ✓ No signup · ✓ Runs in your browser — your data never leaves your device.
How to Use the UUID Generator
- Choose UUID v4 for pure randomness, or v7 if you want IDs that sort by creation time (better for database indexes).
- Set how many you need — from 1 to 500 at once.
- Click Generate. Each UUID is created with the Web Crypto API for cryptographic randomness.
- Copy individual UUIDs or use Copy All to grab the whole batch.
Why Use Our UUID Generator?
- v4 and v7 — random or time-ordered, per the latest UUID standard (RFC 9562).
- Bulk generation — up to 500 UUIDs per click, one per line, ready for seed files.
- Cryptographically secure — built on crypto.randomUUID(), not Math.random().
- Private — generation happens locally; your IDs never touch a server.
Frequently Asked Questions
What is a UUID?
A Universally Unique Identifier: a 128-bit value (like 550e8400-e29b-41d4-a716-446655440000) designed to be unique without central coordination — perfect for distributed systems.
Should I use v4 or v7?
Use v4 for general-purpose unique IDs. Use v7 for database primary keys: its timestamp prefix keeps B-tree indexes from fragmenting the way random v4 keys do.
Are these UUIDs really unique?
v4 UUIDs have 122 random bits — the chance of a collision is so small it's effectively zero, even at billions of IDs.
Is this safe for production IDs?
Yes. Generation uses the browser's cryptographic RNG (crypto.randomUUID), the same primitive Node.js and databases use.
Can I generate UUIDs in bulk?
Yes — up to 500 per click, with one-click copy of the entire batch.