UUID Generator
Generate cryptographically secure UUID v4 identifiers in bulk.
Generated UUIDs
UUIDs are generated locally in your browser using cryptographically secure randomness (crypto.randomUUID).
What is the UUID Generator?
The UUID Generator creates version 4 UUIDs — 128-bit universally unique identifiers with 122 bits of cryptographically secure randomness. UUIDs are the standard way to generate collision-free identifiers without central coordination: database keys, request IDs, file names, correlation IDs, and more.
Generation uses crypto.randomUUID, the browser's cryptographically secure generator, and happens entirely on your machine. You can generate up to 500 UUIDs at once, copy them all, or download them as a text file — one UUID per line.
How to use the UUID Generator
- Choose how many UUIDs to generate (1, 5, 10, 50, 100, or 500).
- Click Generate — results appear instantly, one per line.
- Copy all UUIDs to your clipboard or download them as a .txt file.
- Click Generate Again for a fresh batch.
Examples
UUID v4 format
xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx
The third group always starts with 4 (version); y is one of 8, 9, a, or b (variant).
Sample output
3f2504e0-4f89-41d3-9a0c-0305e82c3301
Frequently asked questions
Are these UUIDs really unique?
With 122 random bits, the probability of two v4 UUIDs colliding is astronomically small — you could generate a billion per second for decades before a collision becomes likely.
Is the randomness secure?
Yes. Generation uses crypto.randomUUID, which draws from your operating system's cryptographically secure random source — and it all happens locally in your browser.
What's the difference between UUID versions?
v4 is purely random (this tool). v1/v6 encode timestamps and node identifiers, v5 derives deterministic UUIDs from names, and v7 combines a timestamp with randomness for sortable keys.
Can I use these as database primary keys?
Yes, v4 UUIDs are widely used as primary keys. If insert-order locality matters for index performance, consider UUIDv7 in your application code instead.
Related developer tools
Hash Generator
Generate SHA-1, SHA-256, SHA-384, and SHA-512 hashes with Web Crypto.
Security & Encoding
JWT Generator
Create and sign JSON Web Tokens with HS256, HS384, or HS512.
Security & Encoding
Base64 Encoder / Decoder
Encode and decode Base64 text with full UTF-8 support.
Security & Encoding
Cron Generator
Build cron expressions visually and translate them to plain English.
Generators