UUID Generator

Generate cryptographically random UUID v4 values — one at a time or in bulk up to 100.

Runs in your browser — your code and data never leave this device


    

    

      
      
    


    


    

      

        
        
      

      

        
        
      

      
      
    

    
Version: v4 (random) — generated with the Web Crypto API for strong randomness.


    

      
      
      
    


    

      
      

    

    

      

        
Count: 0

        
Format: Lowercase, with hyphens

      

    

  


  

    
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How to use the UUID Generator

    
    
      
  1. A UUID is generated automatically when the page loads — copy the big UUID at the top or click New for another.
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  2. Set the quantity (1–100) using the slider or number box to control how many UUIDs appear in the bulk list.
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  3. Toggle Uppercase or Hyphens to change the display format — the list updates automatically.
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  4. Click Generate for a fresh set, Copy all to copy the whole list, or Download .txt to save it as a file.
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Frequently asked questions

    
Is my data uploaded or stored?
No. UUIDs are generated locally in your browser with the Web Crypto API. Nothing is uploaded, logged, or stored on any server.

    
What is a UUID v4?
A UUID (Universally Unique Identifier) is a 128-bit identifier. Version 4 UUIDs are generated from random numbers, with the version and variant bits set so the pattern is xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx where y is 8, 9, a, or b.

    
Can two generated UUIDs ever be the same?
In practice, no. With 122 random bits, the chance of a collision is astronomically small — you would need to generate billions of UUIDs before a duplicate becomes likely.

    
What happens if I turn Hyphens off?
The hyphens are stripped for display, giving a 32-character hex string. The underlying UUID value is the same; some systems prefer the compact form.

    
Where are UUIDs used?
UUIDs are commonly used as database primary keys, session IDs, transaction IDs, file names, and distributed-system identifiers where a central counter is not practical.