Hello Emmanuel, here's a pretty simple implementation of what you might consider doing // Define a global variable to keep track of when this window is in focus var windowFocused = true; // Change the value of the windowFocused variable when the window is no longer in focus window.addEventListener('blur', function(){ windowFocused = false; }, false); // Change the value of the windowFocused variable when the window is in focus window.addEventListener('focus', function(){ windowFocused = true; }, false); // Your setInterval() function setInterval(function() { if (windowFocused) { // Carry out your tasks here console.log('Window focused: ', windowFocused); } }, 1000);