Overview

While Elevar specializes in data accuracy rather than site speed, there are GTM strategies you can use to help.

Well, Can You?

If you go from having hard coded scripts to using a datalayer + Google Tag Manager, you site speed could increase since you're only collecting data once instead of multiple times per script.

However, it depends on the Marketing scripts, on your website setup, and a myriad of other factors.

Typically merchants use Elevar to ensure that as close to 100% of their data is sent to their channels. Site speed is a secondary bonus.

What Can You Do To Help My Site Speed?

From the Google Tag Manager side, we have a few ways to help improve it:

Remove old and unused tags - The less your GTM script needs to load, the faster it can load.
Load marketing tags a little later - We can identify tags that fire on a pageview and have them load in Window Loaded. We can even take it a step further a take the tags that are loading in the Window Loaded and have these fire on a time-loaded trigger. Here's the downside: when you load tags later, you may lose data in your channels. So the accuracy of your channel reporting has the potential to decrease.
Remove visibility tags/triggers - Visibility triggers check every second to see if the specified element in visible on the screen. Because it runs so often, this can affect site speed.
Remove visibility trigger from Google Optimize live or draft tests - Similar to the above, if a live or draft Optimize test is using the visibility trigger, it will also check every second to see if the specified element in visible on the screen. And because it runs so often, it can affect site speed.

From a Dev Side, you could have your developers run a site speed report and identify if there are any recommendations that they would be able to address. Below are two recommended Site Speed Reports your dev team could use:

Wouldn't I be able to Reduce All My Tracking to a Single Stream with Server Side Tracking?

Like Simo Ahava Talks About here? That Would Boost My Site Speed Like Crazy!

That's definitely the goal! The industry isn't quite there yet though because:

Not every marketing channel has a Marketing API available to send tracking data to.
Even the ones that do still recommend sending data through both the browser & the server (e.g. Facebook recommends using both the Pixel & CAPI).

In a future state, server side tagging definitely has the potential to deliver big benefits with site speed!