Bulk UUID generator
Need multiple UUIDs at once? Generate up to 100 random UUID v4 values in one click. Each UUID appears on its own line so you can copy them individually or all at once.
VERSION
COUNT
How it works
UUID v4 generation uses the browser's crypto.randomUUID() API, a cryptographically secure random number generator built into every modern browser. No JavaScript library is needed.
Processing runs in your browser
UUIDs are generated entirely in your browser. All processing happens locally in your browser tab. Our servers are not involved at any point. You can inspect this yourselfin your browser's DevTools Network tab.
Technical specification
UUID version 4 (random) is defined in RFC 4122 (IETF, 2005). A UUID v4 contains 122 random bits; the remaining 6 bits encode the version (4) and variant (10xx in bits 64–65). This tool uses the browser's crypto.randomUUID() method (W3C Web Cryptography API), which provides cryptographically strong randomness from the operating system's CSPRNG, equivalent to /dev/urandom on Linux or BCryptGenRandom on Windows.
- Standard
- RFC 4122: A Universally Unique IDentifier (UUID) URN Namespace
- Random bits
- 122 bits (of 128 total; 6 bits encode version/variant)
- Format
xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx- Collision probability
- ~50% at 2.7 × 10¹⁸ UUIDs generated
Related operations
For hashing identifiers into fixed-width values, try the hash generator. To produce strong random secrets, use the password generator. For encoding identifiers for transport, see Base64.
Frequently asked questions
- How many UUIDs can I generate at once?
- Up to 100 UUIDs per generation. For larger volumes, click Generate multiple times and combine the results.
- Are all generated UUIDs unique?
- Yes. Each UUID is independently generated using crypto.randomUUID() and the probability of duplicates within a set of 100 is effectively zero.
- Can I download the UUIDs?
- Yes. Click the Download button to save all generated UUIDs as a plain text file, one UUID per line.