{devbox/kit} JSON, hashes, JWTs, passwords & more — one page

UUID Generator

Generate random v4 UUIDs or time-sortable v7 UUIDs — one at a time or in bulk.

Runs 100% in your browser•Nothing is uploaded to a server•Free forever

Options

Output


          

          Copied!
        

      

    

  


  

    
About this UUID generator

    
Hit Generate to get a cryptographically random version 4 UUID (RFC 4122), built with crypto.getRandomValues under the hood — the same randomness source used for cryptographic keys, not Math.random(). Set the count to more than one to generate a batch at once, one UUID per line, ready to copy.

    
Version 7 (RFC 9562) is the one to reach for when the IDs become database keys. It puts a 48-bit millisecond timestamp in the leading bytes and fills the rest with randomness, so sorting v7 strings sorts them by creation time. That locality is the whole point: v4 keys scatter across a B-tree index because consecutive inserts land in unrelated places, while v7 keys append, the way an auto-incrementing integer does, without giving up global uniqueness.

    
The v1-style option produces a time-ordered UUID that packs the current timestamp into the same fields a real RFC 4122 v1 UUID uses — but since browsers do not expose a real MAC address, it fills the node ID with random bytes instead of genuine hardware identifiers, so treat it as roughly time-sortable rather than a byte-for-byte spec-faithful v1 UUID. Everything runs locally in your browser — no UUID generated here is ever sent anywhere.


    
More developer tools