AngularJS : Why ng-bind is better than {{}} in angular?

If you are not using ng-bind, instead something like this:

<div>
  Hello, {{user.name}}
</div>

you might see the actual Hello, {{user.name}} for a second before user.name is resolved (before the data is loaded)

You could do something like this

<div>
  Hello, <span ng-bind="user.name"></span>
</div>

if that's an issue for you.

Another solution is to use ng-cloak.


Visibility:

While your angularjs is bootstrapping, the user might see your placed brackets in the html. This can be handled with ng-cloak. But for me this is a workaround, that I don't need to use, if I use ng-bind.


Performance:

The {{}} is much slower.

This ng-bind is a directive and will place a watcher on the passed variable. So the ng-bind will only apply, when the passed value does actually change.

The brackets on the other hand will be dirty checked and refreshed in every $digest, even if it's not necessary.


I am currently building a big single page app (~500 bindings per view). Changing from {{}} to strict ng-bind did save us about 20% in every scope.$digest.


Suggestion:

If you use a translation module such as angular-translate, always prefer directives before brackets annotation.

{{'WELCOME'|translate}} => <span ng-translate="WELCOME"></span>

If you need a filter function, better go for a directive, that actually just uses your custom filter. Documentation for $filter service


UPDATE 28.11.2014 (but maybe off the topic):

In Angular 1.3x the bindonce functionality was introduced. Therefore you can bind the value of an expression/attribute once (will be bound when != 'undefined').

This is useful when you don't expect your binding to change.

Usage: Place :: before your binding:

<ul>  
  <li ng-repeat="item in ::items">{{item}}</li>
</ul>  
<a-directive name="::item">
<span data-ng-bind="::value"></span>

Example:

ng-repeat to output some data in the table, with multiple bindings per row. Translation-bindings, filter outputs, which get executed in every scope digest.