Free UUID Generator
Generate random UUIDs (Universally Unique Identifiers) instantly. Support for UUID v1 and v4, bulk generation, and multiple format options.
UUID Generator
Most commonly used, cryptographically random
Generate 1-100 UUIDs at once
Generated UUID (1)
b157208e-d5c3-41e5-88ec-cf623dd1adbbUUID v4 (Random)
Generated using random numbers. Most commonly used for general-purpose unique identifiers. Collision probability is negligible with proper random generation.
UUID v1 (Timestamp)
Based on timestamp and machine MAC address. Useful when you need time-ordered UUIDs, but may expose timing information.
NIL UUID
Special UUID with all bits set to zero. Used as a placeholder or to indicate absence of a UUID in some systems.
UUID Format Reference
xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx{xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx}urn:uuid:xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxxHow to Use the UUID Generator
Select UUID Version
Choose between UUID v4 (random) or UUID v1 (timestamp-based). Version 4 is recommended for most use cases as it provides maximum randomness.
Set Generation Options
Configure the quantity of UUIDs to generate and select your preferred format: standard lowercase, uppercase, with braces, or without hyphens.
Generate UUIDs
Click "Generate" to create your UUIDs instantly. Generate single UUIDs for quick use or bulk generate hundreds for database seeding.
Copy or Download
Copy individual UUIDs with one click or download all generated UUIDs as a text file for use in your application or database.
Pro tip: Your data is processed entirely in your browser. Nothing is sent to any server, ensuring complete privacy.
Understanding UUIDs
A UUID (Universally Unique Identifier) is a 128-bit number used to uniquely identify information in computer systems. The probability of generating the same UUID twice is so astronomically small that for practical purposes, each UUID can be considered unique without requiring a central registration authority.
UUIDs are standardized by the Open Software Foundation (OSF) as part of the Distributed Computing Environment (DCE). The current standard is defined in RFC 4122. They're widely used in databases, distributed systems, and anywhere unique identifiers are needed without coordination.
Common Use Cases
- Database Primary Keys: Use UUIDs instead of auto-incrementing integers for distributed databases
- Session Management: Generate unique session tokens for web applications
- Distributed Systems: Create unique IDs across multiple servers without coordination
- File Naming: Generate unique file names to prevent collisions
- API Request Tracking: Trace requests through microservices architectures
Frequently Asked Questions
What is a UUID?
A UUID (Universally Unique Identifier) is a 128-bit identifier that is guaranteed to be unique across space and time. Also known as GUID (Globally Unique Identifier), UUIDs are used in software development to uniquely identify information without requiring a central authority.
What is the difference between UUID v1 and UUID v4?
UUID v1 is generated using a timestamp and the MAC address of the computer, making it time-ordered but potentially revealing system information. UUID v4 is generated using random numbers, making it completely random and the most commonly used version for general purposes.
Are UUIDs truly unique?
While not mathematically guaranteed to be unique, the probability of generating duplicate UUIDs is astronomically small. UUID v4 has 122 random bits, meaning you would need to generate 2.71 quintillion UUIDs to have a 50% chance of a collision.
What is a GUID vs UUID?
GUID (Globally Unique Identifier) and UUID (Universally Unique Identifier) are essentially the same thing. GUID is the term used by Microsoft, while UUID is the standard term used in most other contexts. Both follow the same format and generation algorithms.
When should I use a UUID?
Use UUIDs when you need unique identifiers that can be generated independently without coordination. Common uses include database primary keys, distributed systems, session tokens, tracking IDs, and any situation where you need unique IDs without a central database.
What is a NIL UUID?
A NIL UUID is a special UUID where all 128 bits are set to zero (00000000-0000-0000-0000-000000000000). It is used as a placeholder or to indicate the absence of a UUID value in systems that require a UUID format.
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