UUID Generator — Free Online Generator
Generate UUID v4 strings
All processing happens locally. No data is sent to any server.
A UUID (Universally Unique Identifier) is a 128-bit identifier used to uniquely identify information in computer systems. UUID v4 generates random identifiers with an extremely low collision probability — making them ideal for distributed systems where coordination isn't possible. Click Generate to create random UUIDs. You can generate up to 100 UUIDs at once for batch operations. Each UUID follows the standard format: xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx, where the 4 indicates version 4 and y indicates the variant. You can copy individual UUIDs or download the entire batch as a text file for use in your database migrations, seed scripts, or test data generators. UUIDs are commonly used as database primary keys, API identifiers, session tokens, and any situation requiring unique identification. They're especially useful when you need to generate IDs before making a database call, or when building offline-first applications that sync later. The tool uses your browser's cryptographic random number generator for maximum entropy, ensuring each UUID is truly random and unique with near-zero collision probability across trillions of possible values. All generation happens in your browser using the crypto API — your data never leaves your device. For related generation tasks, try our [Hash Generator](/tools/hash-generator) for creating checksums, or use our [Lorem Ipsum Generator](/tools/lorem-ipsum) for placeholder content.
FAQ
What is a UUID?
A UUID (Universally Unique Identifier) is a 128-bit number used to uniquely identify information. The v4 variant generates random UUIDs with near-zero collision probability.
What does "v4" mean?
Version 4 UUIDs are randomly generated. Other versions use different methods like timestamp-based generation (v1) or name-based hashing (v5).
How many UUIDs can I generate?
You can generate up to 100 UUIDs at once. With 2^122 possible v4 UUIDs, the chance of collision is astronomically small.
Is my data safe?
Yes. UUID generation uses your browser's crypto API. No data is sent anywhere.