Free UUID Generator Online
Generate unique UUIDs and GUIDs instantly. Supports UUID v4 (random), v1 (timestamp), bulk generation, multiple formats, and UUID validation.
All generation happens in your browser — no server, no tracking, completely private.
UUID Validator
Paste any UUID to check whether it's valid.
UUID Versions Explained
UUID Version 4 (Random)
Randomly generated using 122 bits of entropy. Most commonly used for databases, APIs, and general-purpose unique IDs.
UUID Version 1 (Timestamp)
Based on the current timestamp and MAC address. Encodes creation time — useful when ordering by creation time matters.
NIL UUID (Zero UUID)
All-zeros UUID: 00000000-0000-0000-0000-000000000000. Used as a null or empty identifier placeholder in UUID-typed fields.
When Do Developers Use UUID Generators?
UUIDs are one of the most essential tools in a developer's toolkit. Here are the most common use cases.
Database Primary Keys
Generate UUIDs for database records instead of auto-increment IDs. UUID primary keys work across distributed systems and prevent ID enumeration attacks.
Session & Token IDs
Create unique session tokens, API keys, and authentication tokens. UUID v4's randomness makes tokens unpredictable and secure.
File & Asset Names
Rename uploaded files with UUIDs to prevent naming conflicts and avoid exposing file metadata in URLs.
Test Data Generation
Generate UUIDs for mock data in unit tests and integration tests where unique identifiers are required.
API Resource Identifiers
Use UUIDs as resource IDs in REST APIs to uniquely identify users, orders, transactions, and other entities.
Distributed Systems
In microservices and distributed architectures, UUIDs allow independent services to create unique IDs without a central coordinator.
Frequently Asked Questions
Common questions about UUIDs, GUIDs, and UUID generation.
A UUID (Universally Unique Identifier), also known as a GUID, is a 128-bit identifier that is unique across space and time. It is formatted as 32 hexadecimal digits in groups like: 550e8400-e29b-41d4-a716-446655440000. UUIDs are used in software development to uniquely identify records, sessions, files, and more.
UUID v4 is randomly generated and is the most commonly used version. UUID v1 is based on the current timestamp and MAC address, so it encodes when and where it was created. For most applications, v4 is recommended because it doesn't expose any machine or timing information.
UUID v4 uses 122 bits of randomness, giving a pool of over 5 undecillion possible values. The probability of generating two identical UUIDs is astronomically small — for practical purposes, UUIDs can be considered universally unique.
GUID (Globally Unique Identifier) is Microsoft's term for the same concept as UUID. They follow the same format and are interchangeable. When developers ask for a GUID generator, they're looking for exactly this tool.
The NIL UUID is a special UUID where all bits are set to zero: 00000000-0000-0000-0000-000000000000. It is typically used to represent a null, empty, or uninitialized identifier in systems that require a UUID type.
Yes. Set the Quantity field to any number from 1 to 100 and click Generate. You can then Copy All to clipboard or Download as a .txt file. No signup required.
WebsToolKit supports: Standard lowercase (default), UPPERCASE, No Hyphens, No Hyphens UPPERCASE, With Braces {}, and Braces with UPPERCASE. Different frameworks and databases may require different UUID formats.
Paste any UUID into the UUID Validator section and click Validate. The tool checks whether it matches the correct UUID format — useful for debugging and verifying UUID data from APIs or databases.
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