UUID Generator

Generate unique identifiers in various formats

About UUID v4

• 128-bit randomly generated identifier

• 2^122 possible UUIDs (extremely low collision probability)

• Format: 8-4-4-4-12 hexadecimal digits

• Version 4 uses random or pseudo-random numbers

Format Examples

Standard:...
Uppercase:...
No Hyphens:...
URN:urn:uuid:...
Braces:{}...
Click 'Add to List' to start building your UUID collection

How to Use This Tool

1

Choose Generation Mode

Select 'Single UUID' for one at a time, 'Bulk Generate' for multiple UUIDs, or 'Validate' to check existing UUIDs.

2

Select Output Format

Choose from standard, uppercase, lowercase, or various bracketed formats to match your needs.

3

Generate UUIDs

Click 'Generate New' for single UUIDs or specify a count for bulk generation (up to 1000).

4

Manage Your Collection

Add individual UUIDs to your list, copy single items or the entire list, and download as a text file.

5

Validate UUIDs

Paste any UUID to validate its format and extract version/variant information.

Pro Tips

  • •UUID v4 uses random values and has an extremely low collision probability (1 in 5.3 x 10^36)
  • •The standard format is 8-4-4-4-12 hexadecimal digits separated by hyphens
  • •You can generate up to 1000 UUIDs at once in bulk mode
  • •The validator accepts UUIDs in multiple formats and normalizes them
  • •Statistics show total count, unique values, and any duplicates (extremely rare)
  • •Use different formats for compatibility with various systems and programming languages

What is a UUID Generator?

A UUID (Universally Unique Identifier) generator creates 128-bit unique identifiers that are practically guaranteed to be unique across space and time. UUIDs, also known as GUIDs (Globally Unique Identifiers), are essential for distributed systems, databases, and applications where unique identification is critical without central coordination. Our UUID generator creates Version 4 UUIDs using cryptographically strong random values, ensuring maximum randomness and uniqueness for your identifiers.

Key Features

Generate UUID v4 with cryptographically strong randomness

Support for multiple output formats (standard, uppercase, lowercase, bracketed)

Bulk generation of up to 1000 UUIDs at once

Real-time UUID validation and format detection

Version and variant information extraction

One-click copy to clipboard for individual or bulk UUIDs

Download generated UUIDs as text file

No server-side processing - all generation happens in your browser

Common Use Cases

Database Records: Create unique primary keys for database tables without relying on auto-increment fields, enabling distributed database systems and preventing ID conflicts during data merges.

Session Management: Generate secure session identifiers for web applications that are impossible to guess and don't reveal information about session creation order or user count.

File and Resource Naming: Ensure unique filenames for uploaded files, temporary resources, or cache keys without worrying about naming collisions in distributed storage systems.

API Development: Create unique request IDs for tracking API calls through distributed microservices, enabling comprehensive logging and debugging across system boundaries.

Testing and Development: Generate test data with guaranteed unique identifiers for unit tests, integration tests, and development databases without manual ID management.

Message Queue Systems: Assign unique identifiers to messages in distributed queue systems for tracking, deduplication, and ensuring exactly-once processing.

Frequently Asked Questions

What is the difference between UUID and GUID?

▼
UUID (Universally Unique Identifier) and GUID (Globally Unique Identifier) are essentially the same thing - 128-bit unique identifiers. GUID is Microsoft's implementation of the UUID standard. Both follow the same format and generation algorithms, with GUID being more commonly used in Windows/.NET environments while UUID is the more universal term.

How unique are UUID v4 identifiers?

▼
UUID v4 identifiers are extraordinarily unique. With 122 bits of randomness (6 bits are used for version/variant), there are approximately 5.3 x 10^36 possible UUIDs. The probability of generating duplicate UUIDs is so low that it's considered negligible - you would need to generate 1 billion UUIDs per second for 85 years to have a 50% probability of one collision.

When should I use different UUID formats?

▼
Use the standard format (lowercase with hyphens) for most applications as it's universally recognized. Uppercase format is common in Microsoft environments and older systems. Bracketed formats like {uuid} or (uuid) are used in Windows Registry, SQL Server, and some configuration files. Choose the format that matches your target system's requirements.

Can UUIDs be predicted or reverse-engineered?

▼
UUID v4 uses cryptographically secure random number generation, making them impossible to predict or reverse-engineer. Unlike UUID v1 which includes timestamp and MAC address information, UUID v4 contains no information about when, where, or by whom it was generated, making it ideal for security-sensitive applications.

Should I store UUIDs as strings or binary in databases?

▼
For optimal storage and performance, store UUIDs as binary (16 bytes) rather than strings (36 bytes). Most modern databases have native UUID/GUID types that store them efficiently. However, if human readability is important or your database doesn't support UUID types, string storage is acceptable with proper indexing.

What are the other UUID versions and when should I use them?

▼
UUID v1 uses timestamp and MAC address (good for sorting by creation time but reveals information). UUID v2 is similar to v1 with DCE Security extensions (rarely used). UUID v3 uses MD5 hashing of a namespace/name (deterministic). UUID v4 uses random values (most common, what we generate). UUID v5 uses SHA-1 hashing (like v3 but more secure). Use v4 for general purposes, v1 for time-sorting needs, and v3/v5 for deterministic generation from existing data.

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