Lazy loading of images is a technique for loading images on a web page only when they are required. This method can improve the page’s loading time without reducing its size. This technique improves overall page performance without compromising page size. To improve page loading speed, we must use Asynchronous ( Async ) and Deferred ( Defer ) attributes in our website’s script execution.
In the preceding context, it is important to consider the use of async and defer attributes. Next, let us look at the problem posed by render-blocking resources, which is a common and frequently identified issue when evaluating website performance, particularly when using tools like page speed insight.
How to Fix Render-Blocking Resources in WordPress
When a website is loading, it downloads and executes multiple components at the same time, including HTML, CSS, and JavaScript files. However, a common issue arises when JavaScript files are executed, causing delays in the rendering and parsing of HTML files. This phenomenon, known as render-blocking resources, is frequently identified as a problem when assessing website performance using tools such as PageSpeed Insight.
To address this issue, a strategic approach includes using the “async” attribute within script tags. By using the “async” attribute, the JavaScript files are loaded asynchronously, allowing the rendering process to continue uninterrupted while the JavaScript files are downloaded and executed simultaneously. This optimization technique helps to create a more seamless and efficient website loading experience, aligning with best practices for improving performance and user experience.
What is Difference Between Async & Defer in Script Loading
When a website is accessed, multiple files, including JavaScript and HTML, are downloaded and processed simultaneously. During this phase, the browser is responsible for interpreting and applying CSS styles, as well as running JavaScript code. However, the arrival and execution of JavaScript files cause a delay, temporarily halting the rendering and parsing of HTML content. This phenomenon is known as “render-blocking resources,” which describes the impediments to seamless website loading caused by such delays. This issue is particularly noticeable in performance analysis tools such as PageSpeed Insight, where recommendations to “eliminate render-blocking resources” may appear. To address this issue, the ‘async’ attribute in script tags is frequently recommended, which allows for the asynchronous loading of JavaScript files and thus improves web page rendering performance.
The ‘defer’ attribute works similarly, allowing for parallel parsing of HTML content while simultaneously downloading JavaScript files. The ‘defer’ attribute ensures that JavaScript execution is postponed, as opposed to non-deferred JavaScript’s immediate execution, which can disrupt HTML parsing. As a result, the JavaScript files are downloaded in the background and stored in the browser’s cache, without interfering with the ongoing processing of the HTML document. The execution of the deferred JavaScript files is strategically delayed until the HTML document is fully parsed. This method significantly speeds up the rendering of HTML content, ensuring that the webpage is visible to the user on time. The deferred execution of JavaScript prioritizes the immediate display of content, with JavaScript functionalities initialized after the HTML structure has been fully loaded and rendered, ensuring an optimized page-loading experience without jeopardizing the HTML parsing process.
Which Images Can Be Lazy Loaded, and Which Can Be Preloaded?
To improve your website’s speed, use a specific approach to loading images, particularly those displayed in the first visible section of a webpage, known as “above the fold.”
However, an exception is advised for the images situated in the top section, or above the fold content. For these images, it is more efficient to pre-load them. Pre-loading involves initiating the download of these images in advance, ensuring they are already present on the user’s device when the webpage is first accessed. This pre-emptive loading minimizes any waiting time for the user, providing a faster and smoother experience.
To improve website performance and user experience, a strategic approach to image loading is necessary. Images in the “above the fold” section, or visible area before scrolling, should be prioritized for immediate loading. Preloading these images ensures that they are fetched and rendered immediately upon page load, providing an uninterrupted viewing experience. Images below the fold, on the other hand, benefit from lazy loading, which defers their download until they reach the viewport. This method significantly reduces the initial load time, saving bandwidth and increasing page speed.
Best & Fastest Lazy Load Plugins in WordPress
Flying Press:
Choosing Flying Press to lazy load your images is a smart move for making your website faster. It makes your site load faster by only bringing in images when they are required, saving time for your visitors. Flying Press is simple to use, works with a variety of website platforms, and ensures that your important images load quickly. So, it’s an excellent choice for speeding up your website and making it more user-friendly.
WP Rocket :
WP Rocket is an excellent choice for lazy loading your images. It’s simple to use, whether you’re a beginner or a professional. WP Rocket accelerates your website by only loading images when visitors are about to see them. This means your website will load faster for visitors. It’s like a magic trick that speeds up your website and makes it great for everyone.
