Some optimisations: - a timeout trick so we don't fire same functions too often (like for keyUp event or updateClasses); - simpler search (indexOf where we had regex); - jQuery animations replaced with velocity, not giving that much improvement; I would get rid of "updateClasses" and the animations altogether

Oluv's bt speaker db - faster search

$.getScript("https://cdn.jsdelivr.net/velocity/1.5.0/velocity.min.js");
$( "#vidText" ).off();

function keyParser(e){
    var q = document.getElementById("vidText").value.split(' ');
    if(q == ''){
        showAll();
        return;
    }
    
    var first = true;
    for (var i = 0; i < videoKeys.length; i++) {
        
        var matchany = true;
        
        $.each(q, function(qkey, qval){
            var nomatch = true;
            
            if(videoKeys[i].toLowerCase().indexOf(qval.toLowerCase()) !== -1)
                nomatch = false;
            
            if(nomatch) matchany = false;
        });
        
        if(matchany){
            if(first){
                $( "#res" + i + ":hidden" ).addClass("first-list-item").css('opacity', 0).slideDown().velocity({ opacity: 1 }, { queue: false, sequenceQueue: false });
                first = false;
            }else{
                $( "#res" + i + ":hidden" ).css('opacity', 0).slideDown().velocity({ opacity: 1 }, { queue: false, sequenceQueue: false });
            }
        }
        else $( "#res" + i ).css('opacity', 1).slideUp().velocity({ opacity: 0 }, { queue: false, sequenceQueue: false }).removeClass("first-list-item");
    }
    updateClasses();
}

var parserTimeout = null;
function startKeyParser(e){
    clearTimeout(parserTimeout);
    parser = setTimeout(function(){
        keyParser(e);
    }, 100);
}

$( "#vidText" ).keyup(startKeyParser);

function showAll(){
    var i = 0;
    $( "#res" + i + ":hidden" ).addClass("first-list-item").css('opacity', 0).slideDown().velocity({ opacity: 1 }, { queue: false, sequenceQueue: false });
	for (i = 1; i < videoKeys.length; i++) {
		$( "#res" + i + ":hidden" ).css('opacity', 0).slideDown().velocity({ opacity: 1 }, { queue: false, sequenceQueue: false });
	}
    updateClasses();
}

var updateCounter = 0;
var updateTimeout = null;
var updateTimeout2 = null;
var updateTimeout3 = null;

function updateClasses(){
    clearTimeout(updateTimeout);
    clearTimeout(updateTimeout2);
    clearTimeout(updateTimeout3);
    updateCounter++;
    updateTimeout = setTimeout(function(){
        oldUpdateClasses(1);
    }, updateCounter*75);
    updateTimeout2 = setTimeout(function(){
        oldUpdateClasses(2);
    }, 200);
    updateTimeout2 = setTimeout(function(){
        clearTimeout(updateTimeout);
        clearTimeout(updateTimeout2);
        oldUpdateClasses(3);
    }, 700);
}

function oldUpdateClasses(z){
	for (var i = 0; i < videoKeys.length; i++) {
		$( "#res" + i ).removeClass("first-list-item").removeClass("last-list-item");
	}
	
	$( ".list-group-item:visible:first" ).addClass("first-list-item");
	$( ".list-group-item:visible:last" ).addClass("last-list-item");
    if(z==1){
        updateCounter = 0;
    }
}