Generate one or more Version 4 UUIDs (universally unique identifiers) with full formatting control. Set the quantity, choose your UUID version, and toggle options like uppercase, hyphens, and braces to get output formatted exactly the way your project needs it.
UUIDs Generated
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Generated UUIDs
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A UUID (Universally Unique Identifier), also known as a GUID (Globally Unique Identifier), is a 128-bit number used to uniquely identify information in computer systems. It is typically represented as a 32-character hexadecimal string split into five groups by hyphens, for example: 550e8400-e29b-41d4-a716-446655440000. The terms UUID and GUID are largely interchangeable, though GUID is more commonly used in Microsoft environments.
Version 4 UUIDs are generated using random (or pseudo-random) numbers, making them the most common type for general use. Except for 6 bits reserved to indicate the version and variant, all 122 remaining bits are randomly assigned. This makes v4 UUIDs highly unpredictable and ideal for most identification tasks where a central authority is not needed.
Functionally, GUIDs and UUIDs are the same thing — both are 128-bit identifiers following the same RFC 4122 standard. The term 'GUID' (Globally Unique Identifier) was popularized by Microsoft, while 'UUID' (Universally Unique Identifier) is the more standard, cross-platform term. You can use them interchangeably in most contexts.
UUIDs are designed to be practically unique without requiring a central registration authority. The probability of generating two identical v4 UUIDs is astronomically low — approximately 1 in 5.3 × 10³⁶. In practice, collisions are so unlikely that UUIDs are considered safe to use as unique identifiers across distributed systems worldwide.
UUIDs are widely used as primary keys in databases, unique identifiers for API resources, session tokens, transaction IDs, file names, and more. They are especially valuable in distributed systems where multiple machines need to generate unique IDs independently, without coordinating with a central server.
The standard UUID format includes hyphens separating five groups of characters (e.g. xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx). Braces (e.g. {xxxxxxxx-...}) are a common format used in Microsoft/COM contexts. Uppercase formatting converts all hex characters to capitals. Quotes wrap each UUID in double quotes, which can be useful when embedding UUIDs in code strings.
Yes — this tool lets you generate between 1 and 100 UUIDs in a single click. You can choose how they are separated (new line, comma, semicolon, or pipe) and apply consistent formatting to all of them at once. The results are displayed in a table for easy copying.
These UUIDs are generated using JavaScript's built-in crypto.getRandomValues() method, which produces cryptographically strong random numbers suitable for most production use cases. However, for highly security-sensitive applications (e.g. cryptographic keys or tokens), consider using a server-side UUID library with a certified random source.