UUID Generator
Generate, validate, and manage universally unique identifiers
UUID Validator
Recent History
What Does This Tool Do?
The UUID Generator 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.
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.