Standard lowercase v4
3f2b6c1e-9a4d-4f77-b2c1-8e5d0a7f2b91
UUID Generator
Generate cryptographically random UUID v4 values in bulk.
Generated with your browser's crypto API, not Math.random().
Generated UUIDs
The result will appear here.
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About this tool
A UUID is a 128-bit identifier written as 32 hexadecimal digits in five hyphen-separated groups. Version 4 is the one almost everyone means: 122 of those bits are random, which is enough that two independently generated values will not collide in any practical system.
That property is the point. Any machine, service or offline client can mint an identifier without asking a central database first, which is why UUIDs turn up in distributed systems, event streams and client-generated records.
How to use it
- Choose how many identifiers you need — from a single value up to a hundred.
- Adjust the format: uppercase, without hyphens, or wrapped in braces for systems that expect the Microsoft GUID style.
- Copy all of them at once, or download the list as a text file.
- Generate again for a fresh batch. Every value is new.
Examples
Microsoft GUID style
Uppercase and wrapped in braces, the form .NET and SQL Server tooling prints.
{3F2B6C1E-9A4D-4F77-B2C1-8E5D0A7F2B91}Common problems
- The database rejects the value as too long.
- A UUID is 36 characters with hyphens, 32 without. Either widen the column, use a native uuid type, or store the hyphen-free form in a CHAR(32).
- UUID primary keys made the database slower.
- Random v4 values scatter inserts across the index instead of appending to the end. For high-insert tables, a time-ordered identifier such as UUID v7 or ULID keeps the locality.
- Two systems disagree about the format.
- Same bytes, different presentation. Normalise to lowercase without braces at the boundary and convert only when you must.