Shopify Web Vitals Debugging Not Working in Firefox

App Bridge
1

Hi everyone,

I’m currently working on optimizing LCP for a Shopify embedded app and have enabled web-vitals debugging using the following meta tag:

<meta name="shopify-debug" content="web-vitals" />

This works perfectly in Chrome, and I’m able to capture metrics using shopify.webVitals.onReport(callback).

However, in Firefox, the debug tool doesn’t seem to work:

  • The meta tag has no effect.
  • The shopify.webVitals.onReport(callback) event is not firing at all.

Has anyone else faced this issue, or is there any known workaround or fix for Firefox?

Any insights would be greatly appreciated.

Thanks in advance!