function simpleController($scope)
{
$scope.tags = ['HTML','CSS','Jquery','Bootstrap','AngularJS'];
}

<div ng-controller="simpleController">
<input  class="txt" type="text" ng-model="nameText" />
<div>
 <ul>
  <li ng-repeat="myKeys in tags| filter:nameText">{{myKeys}}</li>
 </ul>
<div ng-show="!tags.length">No Tag Found</div>
</div>
</div>

<div ng-show="!(tags| filter:nameText).length">No Tag Found</div>