Free Online UUID Generator
Generate RFC4122-compliant UUIDs (v4 & v1) instantly or in bulk for your database and applications
Random v4
Time-based v1
Bulk Generation
100% Unique
Free Forever
Generated UUID v4
Click Generate
Recent Generation History
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Configuration
Output
How to Generate UUIDs
Our free online UUID generator provides valid, unique identifiers in seconds. Here's how to use it:
Single UUID
- Select your preferred version: v4 (Random) or v1 (Time-based).
- Click the big blue Generate button.
- Copy the result to your clipboard with a single click.
- View your recent generation history below the tool.
Bulk Generation
- Switch to the Bulk Generation tab.
- Enter the number of UUIDs you need (up to 5000).
- Click Generate Bulk.
- Copy the entire list or download it as a
.txtfile.
Understanding UUID Versions
UUID stands for Universally Unique Identifier. It is a 128-bit number used to identify information in computer systems. While there are several versions, v4 and v1 are the most common.
| Feature | UUID Version 4 (Random) | UUID Version 1 (Time-based) |
|---|---|---|
| Generation Method | Uses random numbers. | Uses timestamp & MAC address. |
| Uniqueness | Extremely high probability of uniqueness. | Guaranteed uniqueness (if MAC is unique). |
| Privacy | High (Contains no metadata) | Low (Reveals time & node ID) |
| Best Use Case | Primary keys, session IDs, public-facing IDs. | Database sorting by creation time, transaction IDs. |
Frequently Asked Questions
For UUID v4, the probability of a collision is astronomically low—so low that it's effectively impossible in human terms. You would need to generate billions of UUIDs per second for years to reach even a tiny chance of collision. For UUID v1, collisions are impossible within the same namespace if the clock sequence is handled correctly.
Yes. UUIDs are widely used as Primary Keys in databases like PostgreSQL, MySQL, MongoDB, and SQL Server. They allow for distributed systems to generate IDs without a central coordination server.
Our generator produces UUIDs that follow the RFC 4122 standard format (8-4-4-4-12 hex digits). While the v1 generation is simulated client-side (to avoid exposing your actual MAC address for privacy), the structure and validity are fully compliant for application testing and development use.