Content Loaded A playground of loading resources into a web page

async/defer and DOM construction

In this page, you can see visually the behavior of DOM construction according to the presence or absence of the async / defer attribute of the script.

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Script position and page speed

In this page, you can visually verify the relationship between the site speed and the timing of DOM ready in accordance with the position of script installation.

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Responsive Images

Demonstrations of true responsive images to fit the user context responsively and reduce page weight for perceived performance.

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