# "Uncaught ReferenceError: process is not defined" and the solution

The Uncaught ReferenceError: process is not defined 
happens when when a non-existent (here: process) variable is referenced.

Most likely the problematic code snippet looks like:



var isProduction = process.env.NODE_ENV === 'production';    



The process.env property is available on node, 
but not in the browser which causes the above error.


To fix the problem, define the variable pro-actively before the library is loaded, e.g.:

window.process = {
    env: {
        NODE_ENV: 'development'
    }
}    



The fix/script can be loaded with e.g.: 



<script src="init.js"></script>