Prefetch
Definition
Prefetch is a browser feature that allows a website to request that certain resources, such as images or scripts, be loaded into the browser's cache. The purpose of prefetching is to speed up the loading of a webpage by loading resources before they are actually needed.[1]
Types of prefetch
There are different ways of using prefetching, the main ones are:
- dns-prefetch: This prefetch type allows the browser to resolve a domain name before the user clicks on a link, reducing the time required to load a website when the user clicks on the link.
- preconnect: This prefetch type allows the browser to establish a connection to a server before it's needed to load resources, reducing the time required to load a website.
- preload: This prefetch type allows the browser to load resources that are required to load the page before it's requested, reducing the time required to load a website.
- prerender: This prefetch type allows the browser to load the entire page and resources required before the user actually clicks on the link, this allows the page to be rendered and ready before the user clicks on the link.
Implementation
Prefetching can be implemented in different ways, such as by using HTML tags in the head of a webpage, or by using JavaScript to programmatically request resources. The use of prefetching can improve the loading time of a website and provide a better user experience. However, it's important to use it carefully, as prefetching can lead to a higher resource usage and can overload the browser's cache, leading to decreased performance.
Practical relevance
The practical relevance of prefetching is that it can help to speed up the loading of a website, by loading resources before they are actually needed. By using prefetching, a website can reduce the time it takes for a page to load, which can improve the user experience and make the website more engaging and responsive.
Here are a few ways in which prefetching can have practical relevance:
- Faster loading times: Prefetching can reduce the time it takes for a webpage to load by loading resources before they are actually needed. This can lead to a more responsive website, which can improve the user experience.
- Improved user experience: By reducing the time it takes for a webpage to load, prefetching can improve the user experience. This can lead to more engagement, more pageviews, and ultimately more conversions.
- Better performance on mobile devices: Prefetching can be especially useful on mobile devices, as it can help to reduce the amount of data that needs to be downloaded, which can help to improve performance on mobile networks.
- Better performance on single page application: prefetching can be especially useful in Single Page Application(SPA), which require a lot of loading resources, it can improve the performance of the application and decrease loading times.
- Better SEO: Faster loading times can help to improve SEO as search engines like Google use page load speed as a ranking factor. By reducing the time it takes for a webpage to load, prefetching can help to improve search engine rankings.