- Select the UUID version you need: v4 (random, most common), v1 (time-based), or Nil (all zeros)
- Set the quantity of UUIDs to generate (1 to 1000)
- Choose format options: uppercase, remove dashes, or add braces as needed
- Click 'Generate UUID' button to create your UUIDs instantly
- Copy individual UUIDs or all at once, or download as a text file
What is the difference between UUID v1 and v4?
UUID v1 is time-based and includes a timestamp and MAC address, making it sortable by creation time. UUID v4 is completely random, offering better privacy as it reveals no information about when or where it was created. For most applications, UUID v4 is recommended due to its simplicity and privacy benefits.
Are UUIDs truly unique?
While not mathematically guaranteed to be unique, the probability of generating duplicate UUID v4s is astronomically low (about 1 in 2^122). For practical purposes, UUIDs can be considered unique. The total number of possible UUID v4s is approximately 5.3 x 10^36.
What is a Nil UUID used for?
A Nil UUID (00000000-0000-0000-0000-000000000000) is a special UUID where all bits are set to zero. It is often used as a placeholder, default value, or to represent 'no value' in systems that require a UUID format but need to indicate absence of a real identifier.
Is it safe to use this UUID generator?
Yes, absolutely. All UUID generation happens entirely in your browser using JavaScript. No data is transmitted to any server. Your generated UUIDs remain completely private and secure on your device.
Master UUID concepts, versions, and implementation. Learn the differences between UUID v1 and v4, when to use each version, and best practices for generating unique identifiers in distributed systems.