UUIDType
Output format
Batch generate
to generate a unique identifier
UUIDGenerator
UUID（Universally Unique Identifier）This generator is an essential online tool for developers, helping you quickly generate various types of unique identifiers. It supports full generation of UUID1-8 and the Nil UUID, providing a complete identifier management solution for database indexes, distributed systems, microservice architectures, and more。
Key features
🔢 Multiple types supported
Full generation support for all 9 types: UUID1-8 and the Nil UUID。
UUID2：DCE security identifier (deprecated)
UUID3/5：Namespace hash type, deterministic generation
UUID4：Randomly generated type, the most widely used
UUID6：Time-sort-optimized type, index-friendly
UUID7：Modern timestamp type, recommended for cloud-native
UUID8：Custom extension type, flexibly customizable
Nil UUID：All-zero placeholder
📦 Multi-format output
Supports multiple UUID output formats to meet different use cases and system requirements。
- Standard format - xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx
- Uppercase format - XXXXXXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX
- No hyphens - xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
- Braces format - {xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx}
- URNFormat - urn:uuid:xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx
⚡ Batch generate
Generate multiple UUIDs at once to boost development efficiency。
- Batch generation - generate 1-1000 UUIDs at once
- Quick copy - copy all generated UUIDs in one click
- Consistent format - batch-generated UUIDs all share the same format
🛡️ Security
Uses the browser’s native Web Crypto API to ensure the security and randomness of UUID generation。
- Local generation - UUIDs are never uploaded to a server
- Secure random numbers - using crypto.getRandomValues()
- Standards-compliant - strictly follows the RFC 4122 standard
How to use
SelectUUIDType
Choose UUID1-8 or Nil UUID based on your use case, then configure the relevant parameters (such as namespace, name, etc.)
Configure output format
Choose the output format you need, such as standard, uppercase, or no hyphens
Set batch count
To generate in bulk, set the count (1-1000)
Generate and copyUUID
Click"GenerateUUID"button, and the tool will generate the UUID and show detailed information, with copy and download support
UUIDType overview
UUIDis a fundamental identifier for modern distributed systems, with different UUID types suited to different use cases. Choosing the right UUID type is important for both system performance and security。
Type comparison
UUID1 - Time-series identifier
Timestamp-based + MACAddress | Time-ordered | Privacy risk
Generated from a precise timestamp (100-nanosecond precision) and hardware address, containing a 60-bit timestamp, a 14-bit clock sequence, and a 48-bit node ID. Its advantage is time ordering, making it suitable for database indexes that require strict chronological order, but it carries the privacy risk of exposing hardware information. It is typically used in financial transaction systems, distributed logs, and other scenarios that need time traceability。
UUID2 - DCESecurity identifier
Early standard | Deprecated | Legacy systems
An early extended version for distributed computing environments that adds POSIX UID/GID information on top of version 1. It has been phased out by modern systems and is only seen in some legacy systems. Its design reflects the characteristics of early distributed security models and has limited practical value today。
UUID3/5 - Namespace hash-based
MD5/SHA-1Hash | Deterministic generation | Content addressing
Converts a namespace and name into a fixed UUID using a hash algorithm (MD5/SHA-1). Version 3 uses MD5 (128-bit), while version 5 uses the more secure SHA-1 (160-bit). Its key advantage is deterministic generation: the same input always produces the same output, which is commonly used in content-addressed systems. Note that MD5 is no longer recommended for security-sensitive scenarios。
UUID4 - Randomly generated
Fully random | No privacy risk | Most widely used
A UUID generated entirely from cryptographically secure random numbers, containing 122 bits of random entropy. It is simple to implement with no risk of privacy leakage, and is the most widely used version. However, because it is completely unordered, it is not ideal as a direct database primary key. Modern systems usually need extra handling to achieve good indexing performance。
UUID6 - Time-ordered optimized
Time-ordered | Index-friendly | Database optimized
An improved design over version 1 that optimizes database index efficiency by reordering the bytes of the timestamp fields. It preserves time ordering while making the lexicographic order of the UUID strictly match its chronological order, making it especially suitable for high-throughput time-series data storage。
UUID7 - Modern timestamp-based
Unix timestamp | Cloud-native recommended | Microservice architecture
A new standard based on a Unix timestamp (second-level precision) that resolves the privacy issues of version 1. Its design of a 48-bit timestamp combined with 80 bits of random data balances sortability and security, making it the recommended choice for the cloud-native era, especially well suited to microservice architectures。
UUID8 - Custom extensible
Maximum flexibility | Custom use | Experimental protocol
An open framework offering maximum flexibility, where every bit can be customized except the version identifier bits. It supports special business encoding needs or experimental protocol designs, but developers must guarantee uniqueness themselves. It is suited to proprietary systems or special identifier scenarios。
Nil UUID
Nil value | Placeholder | Initialized state
A special all-zeros identifier (00000000-0000-0000-0000-000000000000) used to represent a null or uninitialized state. In system design it is commonly used as a placeholder or default value with clear semantic meaning。
Use cases
🗄️ Database primary key
UUID6/UUID7Recommended: time-ordered and index-friendly
🔗 Distributed systems
UUID4/UUID7Recommended: no privacy risk and excellent performance
📝 Content addressing
UUID3/UUID5Recommended: deterministically generates the same identifier
⏱️ Time series
UUID1/UUID6Recommended: strict time ordering
☁️ Microservice architecture
UUID7Recommended, cloud-native standard
🔧 Special needs
UUID8Recommended: supports custom business encoding
Recommendations
🎯 General use
Recommended: UUID4, simple and reliable with no privacy risk, suitable for most use cases
📊 Database index
Recommended: UUID6 or UUID7, time-ordered and index-friendly with excellent performance
🔐 Security-sensitive
Recommended: UUID4 or UUID7, which avoid exposing hardware information and protect privacy
🔄 Deterministic requirements
Recommended: UUID5 (SHA-1), where the same input produces the same output, ideal for content addressing