Lighthouse audit suggest me to lazy load chat beacon that is implemented via Google Tag Manager. Because this tag is quite big I have been already delay it by adding custom event that fires 1.5 seconds after Window Loaded event and on that custom event I am firing this chat beacon. Should I do anyway lazy loading on this tag? Report says that I could save around 3 second in loading page. If yes how could I make lazy loading tag in GTM and if it is even possible? Bellow I pasted how tag look like. Thank you for any suggestion.
<script type="text/javascript">!function(e,t,n){function a(){var e=t.getElementsByTagName("script")[0],n=t.createElement("script");n.type="text/javascript",n.async=!0,n.src="https://beacon-v2.helpscout.net",e.parentNode.insertBefore(n,e)}if(e.Beacon=n=function(t,n,a){e.Beacon.readyQueue.push({method:t,options:n,data:a})},n.readyQueue=[],"complete"===t.readyState)return a();e.attachEvent?e.attachEvent("onload",a):e.addEventListener("load",a,!1)}(window,document,window.Beacon||function(){});</script>
<script type="text/javascript">window.Beacon('init', 'XXXXXXXXX-XXXX-XXXXXXXXX-XXXXXXX')</script>
And one more question. This tag is attach to the page which means that if we scroll down it will always be in the same place. Lazy loading in this situation I understand as loading beacon after clicking this chat icon?
Yes, in this case lazy loading would be loading on click.
However, people rarely do it. Why? Cuz async loading n.async=!0 won't normally delay anything from the user perspective in any significant way.
And lighthouse is not the last instance of truth. It's just a not-very-good way to generically suggest page speed improvements.
If you want to measure it properly, stop using lighthouse, start using page speed profiling in your browser. Measure the user experience with the chat how it is now, then disable it completely in tag manager and reload the page. See if you're able to find those claimed 3 seconds. Repeat both experiments a few times to compensate for random speed fluctuations. I doubt you will be able to measure any real difference.