UUID Generator
Generate, validate, and manage universally unique identifiers
UUID Validator
Recent History
What is UUID Generator?
The UUID Generator is a free online tool that creates universally unique identifiers (UUIDs) using the Version 4 standard, which relies on cryptographically secure random numbers. UUIDs are 128-bit values commonly used as database primary keys, session tokens, transaction IDs, and anywhere a unique reference is needed without central coordination.
This tool generates UUIDs entirely in your browser using the Web Crypto API, ensuring high-quality randomness and complete privacy. No data is sent to any server. You can generate single or bulk UUIDs, customize their format, validate existing UUIDs, and download results for use in your projects.
Features
Cryptographic Randomness
Uses the Web Crypto API (crypto.getRandomValues) to generate UUIDs with high-entropy randomness suitable for security-sensitive applications.
Bulk Generation
Generate 1, 5, 10, 25, 50, or 100 UUIDs at once. Perfect for populating test databases or creating batches of unique identifiers.
Format Options
Toggle between uppercase and lowercase output, and choose whether to include or remove hyphens to match your project's requirements.
One-Click Copy
Copy individual UUIDs or the entire batch to your clipboard instantly. Each UUID row has its own copy button for quick access.
UUID Validator
Paste any string to check if it is a valid UUID. The validator detects the UUID version and confirms proper formatting.
Download & History
Download generated UUIDs as a text file for offline use. A session history tracks all UUIDs you have generated during your visit.
How to Use
- Select the quantity - Choose how many UUIDs to generate from the dropdown menu (1, 5, 10, 25, 50, or 100).
- Set format preferences - Toggle uppercase if you need capital letters, and toggle hyphens on or off based on your needs.
- Click Generate - Press the Generate button to create your batch of UUIDs instantly in the output area.
- Copy or download - Use the individual copy buttons, Copy All, or Download as .txt to export your UUIDs.
- Validate a UUID - Scroll to the UUID Validator section, paste a UUID, and click Validate to check its format and version.
- Review history - Check the Recent History section to see previously generated UUIDs from your current session.
When Should You Use This Tool?
Use this free online UUID generator whenever you need unique identifiers for database records, API resources, test data, or distributed systems. It is ideal for developers who need quick one-off UUIDs during development, QA testers populating test databases, and anyone who needs to generate bulk identifiers without installing software. The tool runs instantly in your browser with no signup required.
Example Usage
Select a count of 5 from the dropdown, leave hyphens enabled and uppercase off, then click Generate. The tool instantly produces five random UUIDs like:
550e8400-e29b-41d4-a716-446655440000 6ba7b810-9dad-11d1-80b4-00c04fd430c8 f47ac10b-58cc-4372-a567-0e02b2c3d479 7c9e6679-7425-40de-944b-e07fc1f90ae7 a1b2c3d4-e5f6-4789-abcd-ef0123456789
Copy individual UUIDs, copy all at once, or download the batch as a text file for use in your project.
Common Use Cases
- Generate primary keys for database records in distributed systems
- Create unique session tokens and transaction identifiers
- Populate test databases with bulk unique IDs for QA testing
- Generate correlation IDs for tracing requests across microservices
- Create unique filenames and resource identifiers for cloud storage
- Assign unique tracking codes for analytics and event logging
FAQ
What is a UUID?
A UUID (Universally Unique Identifier) is a 128-bit number used to uniquely identify information in computer systems. It is represented as 32 hexadecimal digits displayed in five groups separated by hyphens, following the pattern 8-4-4-4-12 (for example, 550e8400-e29b-41d4-a716-446655440000).
What are the different UUID versions?
There are five standard UUID versions. Version 1 is based on timestamp and MAC address. Version 2 is DCE Security. Version 3 uses MD5 hashing of a namespace and name. Version 4 is randomly generated, which is what this tool produces. Version 5 uses SHA-1 hashing of a namespace and name. Version 4 is the most widely used due to its simplicity and lack of dependency on external information.
What is the probability of a UUID collision?
For UUID v4, the probability of generating a duplicate is astronomically low. With 122 random bits, you would need to generate approximately 2.71 quintillion UUIDs to have a 50% chance of a single collision. In practical terms, if you generated one billion UUIDs per second, it would take about 85 years to reach a 50% collision probability.
Are UUIDs generated here secure?
Yes. This tool uses the Web Crypto API (crypto.getRandomValues), which provides cryptographically secure pseudorandom numbers. All generation happens entirely in your browser with no data sent to any server, ensuring your UUIDs remain private.
Can I use UUIDs as database primary keys?
UUIDs are commonly used as primary keys, especially in distributed systems where multiple nodes need to generate unique IDs independently. However, be aware that random UUIDs (v4) can cause index fragmentation in some databases. Consider using UUIDv7 (time-ordered) or other strategies if sequential ordering matters for your use case.
What is the difference between UUID and GUID?
UUID and GUID (Globally Unique Identifier) refer to the same concept. UUID is the term used in the IETF RFC 4122 standard and is common in Linux and open-source ecosystems. GUID is the term Microsoft uses in Windows and .NET. They follow the same format and are functionally identical.