How can I hide the Android keyboard using JavaScript?

You can now use inputmode=“none” on up to date browsers. See:

https://developer.mozilla.org/en-US/docs/Web/HTML/Global_attributes/inputmode

What you need to do is create a new input field, append it to the body, focus it and the hide it using display:none. You will need to enclose these inside some setTimeouts unfortunately to make this work.

var field = document.createElement('input');
field.setAttribute('type', 'text');
document.body.appendChild(field);

setTimeout(function() {
    field.focus();
    setTimeout(function() {
        field.setAttribute('style', 'display:none;');
    }, 50);
}, 50);

Here is a bullet-proof method that works for Android 2.3.x and 4.x

You can test this code using this link: http://jsbin.com/pebomuda/14

function hideKeyboard() {
  //this set timeout needed for case when hideKeyborad
  //is called inside of 'onfocus' event handler
  setTimeout(function() {

    //creating temp field
    var field = document.createElement('input');
    field.setAttribute('type', 'text');
    //hiding temp field from peoples eyes
    //-webkit-user-modify is nessesary for Android 4.x
    field.setAttribute('style', 'position:absolute; top: 0px; opacity: 0; -webkit-user-modify: read-write-plaintext-only; left:0px;');
    document.body.appendChild(field);

    //adding onfocus event handler for out temp field
    field.onfocus = function(){
      //this timeout of 200ms is nessasary for Android 2.3.x
      setTimeout(function() {

        field.setAttribute('style', 'display:none;');
        setTimeout(function() {
          document.body.removeChild(field);
          document.body.focus();
        }, 14);

      }, 200);
    };
    //focusing it
    field.focus();

  }, 50);
}

I found a simpler solution that requires neither adding element nor a special class. found it there: http://www.sencha.com/forum/archive/index.php/t-141560.html

And converted the code to jquery :

function hideKeyboard(element) {
    element.attr('readonly', 'readonly'); // Force keyboard to hide on input field.
    element.attr('disabled', 'true'); // Force keyboard to hide on textarea field.
    setTimeout(function() {
        element.blur();  //actually close the keyboard
        // Remove readonly attribute after keyboard is hidden.
        element.removeAttr('readonly');
        element.removeAttr('disabled');
    }, 100);
}

You call the function by passing it the input from which the keyboard was opened, or just passing $('input') should also work.