Create UUID, use it like this
Generate UUID v4 using cryptographic random numbers. Can be used for test data and temporary identifiers.
Example usage
UUIDs are expressed as hexadecimal groups of 8-4-4-4-12 digits. You can create up to 100 at a time.
Please note
The probability of collision is very low, but absolute uniqueness is not guaranteed. Also apply uniqueness constraints to real databases.
Step-by-step instructions
- Enter the number to generate between 1 and 100.
- Click Generate UUID to create a version 4 identifier.
- Copy the whole, taking the output values one by one per line.
Value represented by UUID v4
UUID v4 is an identifier that uses random numbers except for the bits that indicate the version and variant. It calls the browser's crypto.randomUUID and does not combine the address of the login account or device. Requires a modern browser and a security context such as HTTPS or localhost.
| Item | Description |
|---|---|
| Format | 8-4-4-4-12 hexadecimal groups |
| version | The first character of the third group is 4 |
| output | One line per UUID |
Frequently Asked Questions
Can I know the creation time from UUID?
Version 4 is not an ID for chronological sorting. If you need the creation time, save a separate time field.
Are there absolutely no duplicates?
The probability of a collision is very small, but not zero. Put uniqueness constraints on the actual repository.
Can I use UUID as a secret authentication key?
Identifiers and access rights are different concepts. The length, expiration, and authority verification of the secret token must be designed separately.
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