An example that shows the difference between the defaultValue and value property:
Change the month/year of the month field, and then click the button below.
The default value is not affected when you change the value of the month field.
<!DOCTYPE html> <html> <body> Month and year: <input type="month" id="myMonth" value="1997-11"> <button type="button" onclick="myFunction()">Test</button> <p id="demo"></p> <script> function myFunction() {//ww w. j a va2 s . com var x = document.getElementById("myMonth"); var defaultVal = x.defaultValue; var currentVal = x.value; if (defaultVal == currentVal) { document.getElementById("demo").innerHTML = "Default value and current value is the same: " + x.defaultValue + " and " + x.value + "<br>Change the month or year of the month field to see the difference!"; } else { document.getElementById("demo").innerHTML = "The default value was: " + defaultVal + "<br>The current value is: " + currentVal; } } </script> </body> </html>