localStorage is used to persist information across multiple sessions. It has a maximum size of 5MB.
Example
You can try to run the following code snippet to check the size allocated −
var sum = 0;
// loop for size
for(var i in localStorage) {
var amount = (localStorage[i].length * 2) / 1024 / 1024;
sum += amount;
document.write( i + " = " + amount.toFixed(2) + " MB");
}
document.write( "Total = " + sum.toFixed(2) + " MB");