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@abha57
Created October 27, 2020 17:28
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preload, prefetch, preconnect
Preload
Generally it is best to preload your most important resources such as images, CSS, JavaScript, and font files.
preload is different from prefetch in that it focuses on fetching a resource for the current navigation.
prefetch focuses on fetching a resource for the next navigation. It is also important to note that preload does not block the window's onload event.
Allows the browser to set resource priority therefore allowing web developers to optimize the delivery of certain resources.
The browser can determine if the request is compliant with the content security policy by referencing what is defined in the as attribute.
An example of preloading fonts. If you are preloading links with CORS enabled resources you must also include the crossorigin attribute.
<link rel="preload" href="https://example.com/fonts/font.woff" as="font" crossorigin>.
Prefetch
prefetch is a low priority resource hint that allows the browser to fetch resources in the background (idle time) that might be
needed later, and store them in the browser's cache.
e.g - HTML: <link rel="prefetch" href="/uploads/images/pic.png">
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