UUID Generator
Generate random, cryptographically secure UUID v4 identifiers, entirely in your browser.
Free to useNo software to install — works in any modern browser.
No signup neededOpen the tool and start straight away.
Runs in your browserNothing you enter is sent to a server.
Works on mobileSame tool on your phone, tablet or desktop.
How it works
- Enter — type or paste your values or text.
- Get the result — it is worked out in your browser.
- Adjust — change the inputs to compare, or copy the result.
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About UUID Generator
Generate UUIDs — universally unique identifiers — for database records, file names, test data or anything that needs an ID nobody else will have. They are created in your browser.
What a UUID looks like
A UUID is 32 hexadecimal characters in five groups, 8-4-4-4-12, for example 3f2b8c1e-9a4d-4e6b-8c2f-1d7a5b9e0c43. This tool creates version 4 UUIDs, which are built from random numbers; the 4 at the start of the third group marks the version.
Will two ever be the same?
A version 4 UUID has 122 random bits. The number of possible values is so large that you could generate billions every second for many years before a duplicate became likely. In practice they are treated as unique without checking a central list — which is exactly why they are useful when several servers create IDs at once.
When to use one
UUIDs fit well when records are created in many places, when IDs must not reveal how many records exist (unlike 1, 2, 3…), or when data from different systems will be merged later.
When not to
Random UUIDs are larger than a simple number and arrive in no particular order, which can slow down some database indexes. Newer version 7 UUIDs start with a timestamp to keep them in order; if your database or framework supports them, they are worth considering for primary keys.
A UUID is an identifier, not a password: don't use one as a secret. For passwords and keys, use the Password Generator.
What a UUID looks like
A UUID is 32 hexadecimal characters in five groups, 8-4-4-4-12, for example 3f2b8c1e-9a4d-4e6b-8c2f-1d7a5b9e0c43. This tool creates version 4 UUIDs, which are built from random numbers; the 4 at the start of the third group marks the version.
Will two ever be the same?
A version 4 UUID has 122 random bits. The number of possible values is so large that you could generate billions every second for many years before a duplicate became likely. In practice they are treated as unique without checking a central list — which is exactly why they are useful when several servers create IDs at once.
When to use one
UUIDs fit well when records are created in many places, when IDs must not reveal how many records exist (unlike 1, 2, 3…), or when data from different systems will be merged later.
When not to
Random UUIDs are larger than a simple number and arrive in no particular order, which can slow down some database indexes. Newer version 7 UUIDs start with a timestamp to keep them in order; if your database or framework supports them, they are worth considering for primary keys.
A UUID is an identifier, not a password: don't use one as a secret. For passwords and keys, use the Password Generator.
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