UUID Generator
Generate RFC-compliant UUIDs (v4, v1, etc.) for unique identifiers in your applications.
UUIDs are generated client-side and never stored or transmitted.
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About UUID Generator
What is a UUID?
A Universally Unique Identifier (UUID) is a 128-bit identifier that is guaranteed to be unique across space and time. UUIDs are used in various applications like databases, distributed systems, and any system requiring unique identifiers.
UUID Versions
- UUID v4: Generated using random numbers, best for most use cases
- UUID v1: Based on timestamp and MAC address
- Nil UUID: Special case with all zeros
Common Use Cases
- Database primary keys
- Distributed systems for avoiding collisions
- Session IDs in web applications
- Transaction identifiers
- File or document identifiers
- API tokens and request IDs
- Cloud resource naming and tracking
Frequently Asked Questions
What is a UUID and when should I use one?
A UUID (Universally Unique Identifier) is a 128-bit identifier guaranteed to be unique across space and time. Use UUIDs for database primary keys, distributed system identifiers, session IDs, transaction tracking, and any scenario requiring unique identifiers without central coordination.
What's the difference between UUID v4 and UUID v1?
UUID v4 uses random numbers and is ideal for most applications due to its simplicity and security. UUID v1 is time-based and includes timestamp and MAC address information, which can be useful for ordering but may reveal system information.
Are UUIDs generated by this tool truly unique?
Yes, UUID v4 uses cryptographically secure random number generation (crypto.randomUUID()) which provides sufficient randomness to virtually guarantee uniqueness. The probability of generating duplicate UUIDs is astronomically small.
Can I generate UUIDs in bulk?
Yes, you can generate up to 100 UUIDs at once. Use the quantity field to specify how many UUIDs you need. All UUIDs can be copied individually or as a batch using the "Copy All" button.
What are the different UUID formats available?
We offer three formats: Standard (with dashes like 123e4567-e89b-12d3-a456-426614174000), UPPERCASE (same but in capital letters), and Plain (without dashes like 123e4567e89b12d3a456426614174000). Choose based on your application's requirements.
Is it safe to use UUIDs as database primary keys?
Yes, UUIDs make excellent primary keys, especially in distributed systems. They eliminate the need for centralized ID generation and prevent conflicts when merging data from multiple sources. However, they use more storage space than auto-incrementing integers.
What is a Nil UUID and when would I use it?
A Nil UUID (00000000-0000-0000-0000-000000000000) is a special UUID with all bits set to zero. It's used to represent "no value" or "null" in systems that require a UUID format but need to indicate absence of a real identifier.
Are my generated UUIDs stored or transmitted anywhere?
No, all UUID generation happens entirely in your browser using client-side JavaScript. No UUIDs are sent to servers, stored in databases, or transmitted over the internet. Your identifiers remain completely private.
Can I use these UUIDs for API tokens or session IDs?
Yes, UUIDs are excellent for API tokens, session IDs, and request tracking. Their randomness and uniqueness make them secure for authentication tokens, though you may want additional security measures like expiration times for sensitive applications.
How do UUIDs compare to other unique identifier systems?
UUIDs offer global uniqueness without coordination, unlike auto-incrementing IDs. They're more secure than sequential IDs (no predictability) but use more storage. They're ideal for distributed systems, merging databases, and scenarios requiring offline identifier generation.
Can I convert between different UUID formats?
Yes, you can change the format setting to convert existing UUIDs. The tool will regenerate UUIDs in your chosen format. Remember that the underlying UUID value changes when you regenerate, so copy your UUIDs before changing formats if you need to keep the same values.
Are there any limitations to the number of UUIDs I can generate?
The tool allows generating up to 100 UUIDs at once to maintain good browser performance. For larger quantities, generate multiple batches. There's no limit to how many times you can use the tool.