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Did you know if your load you LCP image from another origin (e.g. an image CDN) then LCP time may not be reported properly in RUM (but is in CrUX)? Let’s dig into why, and also how we’re looking to fix this very soon… 🧵

I’ve written a long question (on something else) for Barry but decided I’d wait until tomorrow so he could at least have some life on a Sunday - looks like I could have posted it anyway!

I’ve a date soon with a bear, marmalade sandwiches, a jungle in deepest, darkest Peru, and three children neglected by me for the last week. Plus also to give one amazing mum/wife a much needed break from said children. So I won’t be answering any questions for a bit!

😄 but also great to know. Thanks for sharing. I didn't know this but maybe because most external domain lcp images I've come across are on image cdn services

Not all img CDNs offer this. SpeedSize is an example. However, I reached out to them beginning this month to offer TAO as I had a few (Shopify) clients using their solution. And they then added TAO support (though only on request) 🥳