A UUID (Universally Unique Identifier) is a 128-bit number used to identify information in computer systems. The probability of generating duplicate UUIDs is negligible, making them ideal for distributed systems.

What's the difference between UUID v1 and v4?

UUID v4 uses random or pseudo-random numbers, providing 122 bits of randomness. UUID v1 uses timestamp and MAC address, making them sequential and sortable but potentially revealing system information.

GUID (Globally Unique Identifier) is Microsoft's implementation of UUID. It's functionally identical to UUID but often formatted differently with uppercase letters and curly braces, like {3F2504E0-4F89-41D3-9A0C-0305E82C3301}.

Are UUIDs truly unique?

While not mathematically guaranteed to be unique, the probability of generating duplicate UUID v4s is so small (1 in 5.3 x 10^36) that they're considered unique for all practical purposes.

How many UUIDs can I generate?

Our tool allows you to generate up to 50 UUIDs at once. You can generate as many batches as needed, and all generated UUIDs are saved in your session history for easy access.

UUID Generator - Free Online UUID/GUID Generator | Filator

Free Online UUID Generator - Create Unique Identifiers Instantly

Our UUID Generator is the most comprehensive tool for creating universally unique identifiers online. Generate UUID v4, v1, GUID format, or Nil UUIDs with custom formatting options. Perfect for developers, database administrators, and anyone needing unique identifiers for their projects.

Features of Our UUID Generator

✓ Multiple UUID Versions: Generate v4 (random), v1 (timestamp), GUID, or Nil UUIDs
✓ Bulk Generation: Create up to 50 UUIDs at once
✓ Custom Formatting: Uppercase/lowercase, with/without hyphens and braces
✓ One-Click Copy: Copy individual UUIDs or all at once
✓ Download Option: Export UUIDs as a text file
✓ Generation History: Access previously generated UUIDs
✓ Statistics Tracking: See how many UUIDs you've generated and copied
✓ No Registration: Use immediately without signup
✓ Mobile Friendly: Works perfectly on all devices
✓ Fast & Secure: Client-side generation, no data sent to servers

UUID Versions Explained

UUID v4 (Random)

Most commonly used version. Generates 122 bits of randomness, making collisions virtually impossible. Ideal for most applications requiring unique identifiers.

UUID v1 (Timestamp)

Combines timestamp and MAC address. Sequential and sortable, useful for distributed systems where ordering matters. Less private as it may reveal system information.

GUID (Microsoft)

Microsoft's UUID implementation. Functionally identical but typically formatted in uppercase with curly braces: {3F2504E0-4F89-41D3-9A0C-0305E82C3301}.

Nil UUID

Special UUID with all zeros (00000000-0000-0000-0000-000000000000). Used as a null value or placeholder in systems requiring a UUID format.

Common Use Cases for UUIDs

Database Systems

• Primary keys
• Record identifiers
• Distributed databases
• Data migration

Web Development

• Session tokens
• API keys
• File uploads
• Cache busting

Software Development

• Object identifiers
• Transaction IDs
• Message queues
• Distributed systems

UUID Format and Structure

A standard UUID is a 128-bit number displayed as 32 hexadecimal digits, typically shown in five groups separated by hyphens: xxxxxxxx-xxxx-Mxxx-Nxxx-xxxxxxxxxxxx

• 8-4-4-4-12: Standard grouping format (32 hex digits total)
• M: Version number (1-5)
• N: Variant (8, 9, A, or B for RFC 4122 UUIDs)
• Total of 340,282,366,920,938,463,463,374,607,431,768,211,456 possible UUIDs

Frequently Asked Questions

Which UUID version should I use?

UUID v4 is recommended for most use cases. It provides excellent randomness and no collision risk. Use v1 only if you need sortable, timestamp-based UUIDs and don't mind potentially exposing system information.

Can I use UUIDs as database primary keys?

Yes! UUIDs are excellent for distributed systems where you can't rely on auto-incrementing integers. However, they use more storage (16 bytes vs 4-8 bytes for integers) and may impact index performance.

Are the UUIDs generated here cryptographically secure?

Our UUID v4 generator uses JavaScript's crypto.getRandomValues() when available, providing cryptographically strong random values. For security-critical applications, always verify your randomness requirements.

Pro Tips for Using UUIDs

📌 Store UUIDs as binary (16 bytes) in databases for better performance
📌 Use UUID v4 for maximum randomness and privacy
📌 Consider using shorter alternatives like nanoid for user-facing IDs
📌 Index UUID columns properly in databases for query performance
📌 Use consistent formatting across your application

Privacy Note: All UUIDs are generated locally in your browser. No data is sent to our servers, ensuring complete privacy and security of your generated identifiers.

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