olark.configure('box.start_hidden', true);

Notes

Suppose you usually show the chatbox, but wish to hide it on specific pages. You can do so using the following Javascript API function. You can enable this option on your Setup page as Hide the chatbox by default.

The api.box.hide function is useful for when the chatbox has already loaded on a site and you wish to hide it again. For example, when the visitor clicks a particular button.

You would use box.start_hidden when you don’t want the chatbox to show at all when the page loads. If you used api.box.hide to hide the chatbox when the page loads, a visitor might see the chatbox appear briefly, before the API call was read.