|April 19th, 2019|
|tech, amp [html]|
It's designed for pre-rendering. The AMP JS knows when it's being speculatively rendered and prioritizes the most important and cheapest things. Additionally, this pre-rendering can happen in a privacy-preserving way
In the non-preloaded case, taking a random post here, I see a median speed index of 1.611s on non-AMP but 2.051s on AMP. In both cases the HTML loads in ~400ms, but the HTML version can paint the HTML right away while the AMP version is still waiting on JS. Then the AMP version spends 600ms downloading and executing the AMP runtime and extension scripts. Once AMP has loaded it's smarter than the HTML version about what to load, deprioritizing below the fold resources, but it's already too far behind to catch up. The HTML page is fully loaded in about the time it takes the AMP page to finish rendering above the fold.
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