UUID/GUID Generator
Generate unique identifiers (UUID v4, v7, v1, Nil, Max) with bulk generation support. Includes UUID validator and multiple output formats: all client-side.
UUID/GUID Generator
Generate unique identifiers (UUID v4, v1, Nil, Max)
v4: Random UUID, most commonly used. Cryptographically secure random numbers.
About UUIDs
What is a UUID Generator?
A UUID generator is a tool that creates Universally Unique Identifiers (UUIDs): also known as GUIDs (Globally Unique Identifiers). UUIDs are 128-bit identifiers formatted as 32 hexadecimal characters in five groups separated by hyphens (e.g., 550e8400-e29b-41d4-a716-446655440000). They are designed to be unique across space and time without requiring a central registry: making them ideal for distributed systems, database primary keys, session IDs, and API resource identifiers.
CodeHelper's UUID/GUID Generator uses the browser's native crypto.randomUUID() for cryptographically secure v4 UUIDs and supports bulk generation of up to 1,000 identifiers at once.
UUID Versions Explained
- UUID v4 (Random): The most widely used version: 122 bits of cryptographically random data. Virtually collision-free for all practical applications.
- UUID v7 (Time-ordered): RFC 9562, a 48-bit Unix millisecond timestamp followed by random bits. Sorts by creation time, so it is the modern choice for database primary keys.
- UUID v1 (Timestamp): Based on the current timestamp and a node id. Sortable by creation time but reveals timing information.
- Nil UUID: All zeros (
00000000-0000-0000-0000-000000000000): used as a null or default value in systems that require UUID format. - Max UUID: All ones (all f's): the maximum possible UUID value, used in some range-query contexts.
How to generate a UUID
- Select the UUID version (v4 Random, v7 Time-ordered, v1 Timestamp, Nil, or Max).
- Choose the output format: standard, no hyphens, uppercase, braces, or URN.
- Set the quantity for bulk generation (1 to 1,000 UUIDs).
- Click Generate to produce the identifiers.
- Copy individual UUIDs, copy all, or download as a text file.
Whether you are creating database primary keys, generating session tokens, building distributed systems, or seeding test data, this free UUID generator produces cryptographically secure identifiers instantly with no server-side processing.
UUID or GUID? Same thing, two names
GUID (Globally Unique Identifier) is Microsoft's name for the same 128-bit identifier the rest of the industry calls UUID (Universally Unique Identifier). A GUID from C#'s Guid.NewGuid() and a UUID v4 from this generator are structurally identical: 32 hex digits in the 8-4-4-4-12 layout. Whatever your stack calls them, this tool generates them, one at a time or in bulk.
Frequently Asked Questions
What is the difference between a UUID and a GUID?
Nothing structural: GUID is the Microsoft ecosystem name, UUID is the standard name (RFC 4122). Both are 128-bit identifiers written as 32 hexadecimal digits in five groups (8-4-4-4-12). A GUID generated in .NET and a UUID v4 generated here are interchangeable.
What is the difference between UUID v1 and v4?
UUID v1 is built from a timestamp plus a node identifier, so it sorts roughly by creation time but can leak when and where it was generated. UUID v4 is 122 bits of pure randomness, which makes it the safe default for database keys, tokens and public identifiers. Use v1 only when time ordering matters more than opacity.
Can two random UUIDs collide?
In theory yes, in practice no. UUID v4 has 122 random bits, so you would need to generate about 2.7 quintillion UUIDs to reach a 50 percent chance of a single collision. For any realistic system, collisions are not a design concern.
Are the UUIDs generated here secure and private?
Yes. Generation uses the cryptographically secure random source of your own browser (crypto.getRandomValues) and runs entirely client side: no generated identifier is ever sent to, or known by, any server. That also means they are safe to use immediately in production systems.
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