What is a UUID and why do I need one?

A UUID (Universally Unique Identifier) is a 128-bit identifier guaranteed to be globally unique. You need UUIDs for database primary keys, distributed systems, session tokens, file names, and any scenario requiring collision-free unique identifiers.

What's the difference between UUID v4 and v7?

UUID v4 is completely random and widely supported. UUID v7 includes Unix timestamp milliseconds making it sortable by creation time, which improves database index performance and is the modern recommended standard for new applications.

How many UUIDs can I generate before collision?

UUID v4 has 122 bits of randomness. You'd need to generate 2.71 quintillion (2.71 × 10^18) UUIDs to have a 50% chance of collision. For practical purposes, collisions are impossible with proper implementation.

Which UUID version should I use for database primary keys?

UUID v7 is recommended for database primary keys because it's time-ordered, improving B-tree index efficiency and query performance. Avoid v4 for high-volume databases as random ordering causes index fragmentation.

Can I generate UUIDs offline?

Yes! This UUID generator works 100% client-side using the Web Crypto API. All generation happens in your browser with no server dependency, ensuring privacy and offline functionality.

What are namespace UUIDs (v3 and v5)?

Namespace UUIDs (v3 uses MD5, v5 uses SHA-1) generate deterministic UUIDs from a namespace and name. Same inputs always produce the same UUID, useful for idempotency and content-addressable systems.

How do I extract timestamps from UUIDs?

UUID v1, v6, and v7 contain timestamps. v1 and v6 use 100-nanosecond intervals since 1582, v7 uses Unix epoch milliseconds. Use our Parse feature to automatically extract and decode timestamps.

Is UUID generation cryptographically secure?

Yes. We use crypto.randomUUID() and crypto.getRandomValues() from the Web Crypto API, which uses a cryptographically secure pseudo-random number generator (CSPRNG) suitable for security-sensitive applications.

Can I use UUIDs as API keys or passwords?

No. UUIDs are identifiers, not secrets. For API keys or tokens, use dedicated cryptographic functions designed for authentication. UUIDs lack the entropy and format requirements for secure credentials.

How do I bulk generate millions of UUIDs?

Use our Bulk Generate feature supporting up to 10 million UUIDs. Select your desired version, quantity, and export format (JSON, CSV, SQL, YAML). Generation is optimized for performance and memory efficiency.

What is the UUID v6 version?

UUID v6 is a reordered version of v1, placing timestamp bits in big-endian order for better database sorting. It maintains v1's timestamp precision while improving lexicographic ordering for indexed storage.

Do UUIDs contain personal information?

UUID v1 contains your MAC address (hardware identifier), which is a privacy concern. We recommend v4 (random) or v7 (timestamp + random) which contain no personal information. All other versions are privacy-safe.

Professional UUID Generator — All Versions v1-v8

Generate,validate, parse, and analyze UUIDs with support for all RFC 4122 versions. Bulk generation, format conversion, timestamp extraction, collision analysis, and enterprise-grade features. 100% free, privacy-first, cryptographically secure.

UUID Generator & Validator

v4 (Random)

v1 (Timestamp)

v3 (MD5)

v5 (SHA-1)

v6 (Reordered)

v7 (Unix Time)

Bulk Generate

🎯 Generate UUID v4

Generated UUID(s)

Click "Generate" to create UUID

Version

Count

Time (ms)

—

Format

Standard

Format Conversion

Standard

Hex

Base64

URN

Binary

📊 UUID Analysis & Info

Generate or validate a UUID to see detailed analysis

Version & variant detection
Timestamp extraction (v1/v6/v7)
Field breakdown (time, clock, node)
Validation status
Format compliance

⚠️ Collision Probability

UUIDs Generated

Collision Chance

Probability calculated for UUID v4 using birthday paradox formula

Professional UUID Generator — All Versions v1-v8

UUID Generator & Validator

🎯 Generate UUID v4

📊 UUID Analysis & Info

⚠️ Collision Probability

⚡ Quick Actions & Tools