UUID v4 Generator
Generate universally unique identifiers (UUIDs) compliant with RFC 4122, version 4.
How the UUID v4 Generator works
Use the UUID v4 Generator to create unique identifiers. You can specify how many UUIDs you need. The tool generates version 4 UUIDs, which are based on random numbers.
First, set the "How many" field. This number determines how many unique identifiers the tool will generate. For example, enter '5' to get five distinct UUIDs.
The "Version" field is pre-selected to 'v4'. This ensures that all generated UUIDs are version 4. Version 4 UUIDs use random numbers for most of their bits, ensuring high uniqueness without revealing information like MAC addresses or timestamps.
Click the 'Generate' button to see your results. The tool will display a list of unique UUIDs based on your input.
Formula used
128 random bits, with version and variant bits set (RFC 4122 v4)
| Symbol | Meaning |
|---|---|
| count | how many identifiers to generate |
| version | v4 — random, no MAC address or timestamp leaks |
UUID v4 is random rather than sequential, so it does not reveal creation order or machine identity, and collision odds are negligible for any realistic dataset. Ideal for database keys, test fixtures and request tracing.
Inputs used: How many, Version.
Worked example
Here is an example of generating a single UUID v4.
- Enter '1' in the "How many" field.
- Ensure the "Version" field is set to 'v4'.
- The tool will generate one UUID, such as: c0a93956-050e-4b1d-8a9f-1894eacff1fc.
Result:
- list: d3818b4f-8ccd-4a69-93ea-a319337a7391
- count: 1
Frequently asked questions
- What is a UUID v4?
- A UUID v4 is a universally unique identifier generated using random numbers. It is a 128-bit number used to uniquely identify information in computer systems.
- Are UUID v4s truly unique?
- The probability of two randomly generated UUID v4s being identical is extremely low. For practical purposes, they are considered unique.
- When should I use a UUID v4?
- Use UUID v4s when you need a unique identifier that does not reveal information about its creation time or the machine that generated it, such as for database primary keys or distributed system IDs.
- Can I generate multiple UUIDs at once?
- Yes, you can specify the number of UUIDs you need. The tool will generate that many unique identifiers in a list.
- What formula does the UUID v4 Generator use?
- It uses 128 random bits, with version and variant bits set (RFC 4122 v4), where count is the how many identifiers to generate; version is the v4 — random, no MAC address or timestamp leaks.
- How do I read the result?
- UUID v4 is random rather than sequential, so it does not reveal creation order or machine identity, and collision odds are negligible for any realistic dataset. Ideal for database keys, test fixtures and request tracing.