UUID Generator
Generate UUIDs in bulk with v4 random and v1 timestamp versions
UUID 生成配置
About this tool
The UUID generator creates Universally Unique Identifiers in bulk:
- UUID v4: random based, the most common version
- UUID v1: timestamp and MAC based, simulated entirely in the browser
- Bulk output: 1 to 100 values at once
- Format options: upper or lower case, hyphens and braces on or off
- Copy: one value or the whole list
What is a UUID
A UUID is a 128-bit identifier written as an 8-4-4-4-12 hexadecimal string, for example 550e8400-e29b-41d4-a716-446655440000. The chance of a collision is extremely low, which makes it a good unique ID for distributed systems.
When to use it
- Database primary keys
- Unique IDs across distributed services
- File or asset identifiers
- Session tokens
- Test data
Versions
- UUID v4: random, with a collision chance around 2 to the power of -122, and the usual choice
- UUID v1: based on a timestamp and MAC address, ordered in time but able to leak host details
- Format: 8-4-4-4-12, 32 hexadecimal characters in total, for example
550e8400-e29b-41d4-a716-446655440000 - Uniqueness: the space holds 2 to the power of 128 values, about 3.4 times 10 to the power of 38