Updated: April 23, 2026
If you’ve been staring at your GA4 reports and noticed that Average Engagement Time stubbornly shows 0m 00s, don’t panic. You’re not alone, and your tracking isn’t necessarily broken.
I’ve seen this issue pop up in a lot of setups, and the good news is that it’s usually not a bug. It comes down to how GA4 actually calculates engagement time — and a few common scenarios where it simply can’t do its job.
Let’s break down what’s going on.
How GA4 Calculates Engagement Time
Before we dive into the causes, it helps to understand what GA4 is trying to do under the hood.
GA4 uses the user_engagement event (and a parameter called user_engagement_msec) to track how long someone is actually interacting with your page. It’s based on browser signals like page visibility, focus, and session activity.
Here’s the catch: if that event doesn’t fire, GA4 has nothing to report. And in certain environments, it just won’t fire.
Reason #1: The Shopify Custom Pixel Problem
If you’re running GA4 through Shopify Custom Pixel, this is likely your culprit.
Shopify Custom Pixels run in a sandboxed environment. They don’t have full access to browser lifecycle APIs — the same APIs that GA4 relies on to detect page visibility, focus, and user interaction. Without those signals, the user_engagement event can’t fire properly.
I’ve seen many cases where a Shopify store looks like it’s tracking fine — pageviews come through, events fire — but engagement time is flat zero. That’s the sandbox at work.
What to do instead: Avoid relying on Shopify Custom Pixel for GA4. Use Shopify’s native GA4 integration or a proper theme-based installation instead. Server-side tracking can also help as a supplementary option, but it won’t fix the engagement signal issue on its own.
Reason #2: Missing user_engagement Event
Even outside of Shopify, the user_engagement event can fail to fire in certain conditions:
- Restricted environments — iframes, embedded content, or pages loaded in a limited browser context
- Very short sessions — if a user lands and leaves before the engagement check runs
GA4 doesn’t fire the user_engagement event continuously. It’s triggered based on browser signals, and if those signals aren’t available (or the session is too brief), the event simply doesn’t happen.
This isn’t a bug. It’s a limitation of how GA4 works in the real world, and honestly, there’s no direct fix for it beyond ensuring your tracking environment supports the necessary APIs.
Final Words
Seeing 0m 00s for Average Engagement Time in GA4 can be frustrating, especially when everything else seems to be working fine. But in most cases, it comes down to one of three things: a sandboxed environment (Shopify Custom Pixel), missing browser signals in restricted contexts, or genuinely low engagement.
The most common fix I see is switching away from Shopify Custom Pixel to a proper GA4 integration. The other causes are harder to “fix” directly — they’re more about understanding the limitations and designing your tracking setup around them.