UUID Generator
Free online UUID v4 generator. Supports bulk generation up to 100 UUIDs, hyphen/no-hyphen format options, and UUID validation. No installation required.
UUID Generator
UUID Validation
Recent History
What is a UUID Generator?
A UUID (Universally Unique Identifier) is a 128-bit identifier that is globally unique. This tool generates UUID v4 (random-based) and supports bulk generation with various formatting options.
UUIDs are used wherever unique identifiers are needed, such as database primary keys, API tokens, session IDs, and file names.
Key Features
- UUID v4 Generation: Generates cryptographically secure random UUIDs.
- Bulk Generation: Generate up to 100 UUIDs at once.
- Format Options: Choose between uppercase/lowercase and with/without hyphens.
- UUID Validation: Verify if an input UUID is valid and display version information.
- Generation History: View recently generated UUIDs within the session.
How to Use
- Set Options: Choose the count, case style, and whether to include hyphens.
- Click Generate: UUIDs will be generated according to your settings.
- Copy: Click the copy button or select directly from the result area.
- Validate: Enter a UUID and click validate to check its validity and version info.
UUID Version Guide
| Version | Generation Method | Characteristics |
|---|---|---|
| v1 | Timestamp + MAC Address | Traceable creation time, MAC address exposure risk |
| v4 | Random | Most widely used, extremely low collision probability |
| v5 | Namespace + Name (SHA-1) | Same input produces same UUID |
| v7 | Timestamp-based (Latest) | Time-sortable, ideal for database indexing |
This tool generates the most versatile UUID v4.
Who Should Use This Tool?
- Backend Developers who need unique keys for database design
- Web Developers who need to generate API tokens or session IDs
- QA Engineers who need to create test data
- System Administrators who need unique names for files or resources
Frequently Asked Questions
What is the collision probability of UUID v4?
UUID v4 uses 122 bits of random data. Even if you generate 1 billion UUIDs, you would need approximately 2.71 x 10^18 UUIDs to reach a 50% collision probability. Practically speaking, collision is not a concern.
Can I remove the hyphens?
Yes, hyphens are only for readability and removing them does not affect UUID validity. However, some systems may require a specific format.
Which is standard – uppercase or lowercase?
RFC 4122 recommends lowercase, but uppercase is also valid. The important thing is to maintain consistency.
Are the generated UUIDs secure?
This tool uses the browser’s crypto.randomUUID() or crypto.getRandomValues() to generate cryptographically secure random numbers.