🆔 Free UUID Generator — No Signup Required

UUID Generator — Generate Secure UUIDs v4, v1 Free Online

Generate cryptographically secure UUIDs v4, v1 and NIL. Bulk generate up to 50 UUIDs at once.

Free · No signup · No data stored · Instant results

What Is UUID Generator?

The ToolForge UUID Generator creates cryptographically secure Universally Unique Identifiers (UUIDs) instantly. Generate UUID v4 (random), UUID v1 (time-based) or NIL UUIDs individually or in bulk. UUIDs are used as unique identifiers in databases, APIs, distributed systems and software development. All generation uses the Web Crypto API for true randomness.

Key Features

UUID v4 — cryptographically random

UUID v1 — time-based generation

NIL UUID — all zeros for testing

Bulk generate up to 50 UUIDs at once

Copy single or all UUIDs with one click

Uppercase and lowercase format options

With or without hyphens formatting

Uses Web Crypto API for secure randomness

How to Use

Select UUID version

Choose UUID v4 (random), v1 (time-based) or NIL from the options.

Choose quantity

Select how many UUIDs to generate — from 1 to 50 at once.

Copy and use

Copy individual UUIDs or all generated UUIDs to your clipboard.

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Who Uses This Tool?

💻 Backend Developers

Generate UUIDs for primary keys in databases to avoid sequential ID guessing attacks.

🔧 API Development

Create unique identifiers for resources, sessions and API tokens.

🧪 Testing

Generate bulk UUIDs for populating test databases and mock data.

🎓 Students

Learn about UUID standards, distributed systems and unique identifier design.

About UUID Generator

UUIDs (Universally Unique Identifiers) are 128-bit identifiers designed to be unique across all time and space without requiring a central registration authority. The standard format is 32 hexadecimal digits displayed in 5 groups separated by hyphens: xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx.

UUID v4 is the most commonly used version. It generates a random 128-bit number with specific bits set to identify it as version 4. The probability of generating two identical v4 UUIDs is astronomically low — approximately 1 in 5.3 × 10³⁶.

UUID v1 generates identifiers based on the current timestamp and the machine's MAC address. This makes v1 UUIDs time-sortable, which is useful for database indexing. However, they embed time information which may be a privacy consideration in some contexts.

The ToolForge UUID Generator uses the Web Crypto API for v4 generation, ensuring true cryptographic randomness. Bulk generation allows developers to quickly populate test databases or generate large sets of unique identifiers for batch operations.

Frequently Asked Questions

What is a UUID?

A UUID (Universally Unique Identifier) is a 128-bit number used to uniquely identify information in computer systems. Standard format: xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx.

What is the difference between UUID v4 and v1?

UUID v4 is randomly generated using cryptographic randomness. UUID v1 is based on the current timestamp and is time-sortable, making it useful for ordered database records.

Are generated UUIDs truly unique?

UUID v4 uses cryptographic randomness making collisions virtually impossible. The probability of generating the same UUID twice is approximately 1 in 5.3 × 10³⁶.

Can I generate multiple UUIDs at once?

Yes. The bulk generation feature lets you generate up to 50 UUIDs at once and copy them all to your clipboard.