Select2 limit number of tags

$("#keywords").select2({
    tags : true,
    width :'100%',
    tokenSeparators: [','],
    maximumSelectionLength: 5,
    matcher : function(term,res){
        return false;
    },
    "language": {
        'noResults': function(){
            return "Type keywords separated by commas";
        }
    }
}).on("change",function(e){
    if($(this).val().length>5){
        $(this).val($(this).val().slice(0,5));
    }
});

Try like this. It'll short up to 5 keywords.

method 1

$("#tags").select2({
    maximumSelectionLength: 3
});

method 2

<select data-maximum-selection-length="3" ></select>

list of all available options https://select2.org/configuration/options-api

Sure, with maximumSelectionLength like so:

$("#tags").select2({
    maximumSelectionLength: 3
});

Maximum Selection Length

Select2 allows the developer to limit the number of items that can be selected in a multi-select control.

http://ivaynberg.github.io/select2/

It has no native callback, but you can pass a function to formatSelectionTooBig like this:

$(function () {
    $("#tags").select2({
        maximumSelectionLength: 3,
        formatSelectionTooBig: function (limit) {

            // Callback

            return 'Too many selected items';
        }
    });
});

http://jsfiddle.net/U98V7/

Or you could extend formatSelectionTooBig like this:

$(function () {
    $.extend($.fn.select2.defaults, {
        formatSelectionTooBig: function (limit) {

            // Callback

            return 'Too many selected items';
        }
    });

    $("#tags").select2({
        maximumSelectionLength: 3
    });
});

Edit

Replaced maximumSelectionSize with the updated maximumSelectionLength. Thanks @DrewKennedy!

The accepted answer doesn't mention that the maximumSelectionLength statement should be inside the document.ready function. So for anyone who is having the same trouble I did, here is the code that worked for me.

 $(document).ready(function() {

          $("#id").select2({
            maximumSelectionLength: 3
          });

        });