UUID Generator
Generate random UUIDs (v4) for development and testing.
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About This Tool
Generate cryptographically random UUID v4 identifiers individually or in bulk. Copy a single UUID or generate up to 100 at once for database seeding, API testing, or unique identifier needs. Uses the Web Crypto API for true randomness, producing RFC 4122 compliant UUIDs. All generation happens client-side with nothing stored or transmitted.
How to Use
- Click Generate to create a new UUID instantly.
- Use the bulk slider to generate up to 100 UUIDs at once.
- Click Copy to copy the result to your clipboard.
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Frequently Asked Questions
- What is a UUID?
- A UUID (Universally Unique Identifier) is a 128-bit identifier formatted as 32 hexadecimal characters separated by hyphens (e.g. 550e8400-e29b-41d4-a716-446655440000). UUID v4 uses random numbers, making collisions virtually impossible.
- Are the generated UUIDs truly random?
- Yes. This tool uses the Web Crypto API (crypto.randomUUID or crypto.getRandomValues) for cryptographically secure random generation.
- Can I generate multiple UUIDs at once?
- Yes. Use the bulk slider to generate up to 100 UUIDs in a single click, perfect for database seeding or test data.
- What is the difference between UUID versions?
- UUID v1 uses timestamps and MAC addresses, v3 and v5 use namespace-based hashing (MD5 and SHA-1 respectively), and v4 uses random numbers. Version 4 is the most common for general-purpose unique identifiers because it requires no coordination or input data.
- Will two UUIDs ever be the same?
- In practice, no. A UUID v4 has 122 random bits, giving roughly 5.3 x 10^36 possible values. You would need to generate about 2.7 x 10^18 UUIDs before having a 50% chance of a single collision, which is far beyond any realistic use case.