What is Progressive Rendering?


Have you ever measured the loading speed of your website? If No, there are lots of tools available on the internet to test the website speed. Search for anyone and measure it. If the website loading speed is more than 3 seconds, it means you are losing a total of 32% of visitors, according to the survey done by Google.

So, it helps if you take action to decrease your website's loading speed, and here progressive rendering comes into the picture, which allows developers to increase the loading speed of the website.

What is Progressive Rendering?

Before discussing the progressive rendering technique, let’s try to understand the progressive rendering word. So, progressive means showing one after another like normal progress, which you may have seen while downloading or uploading the files or even updating the mobile applications.

The meaning of the rendering is showing the content on the web page. So, the full meaning of the progressive rendering word is showing the different components of the web page one after another rather than showing the whole content together.

Here is the definition of progressive rendering.

Progressive rendering is a technique in which web developers break the code of the web page into smaller and more manageable chunks and show all chunks one after another to increase the web page's performance.

How Does Progressive Rendering Work?

Now, let’s understand how progressive rendering works.

If we render the normal webpage on the browser, it loads every content of the web page together, including HTML, CSS, and JavaScript. But in progressive rendering, developers require to break down the code into smaller parts for progressive rendering, as discussed in the above section.

In the first part of the rendering, the website should load components such as the header, body backgrounds, or main intractable parts of the web page. After that, the website should start loading the CSS to style the components. So visitors can start interacting with the web pages.

After that, we require to load a remaining HTML component with CSS and JavaScript to add the behaviour into the code. Also, we should load the JavaScript asynchronously.

Whenever we require to show the images or any content after downloading or getting data from API, that should show at last.

Different Techniques to Implement the Progressive Rendering

Now, we will learn the different ways to implement progressive rendering on the website.

Lazy Loading

As the name suggests, it loads the web page's content lazily. In the lazy loading technique, we can only load the web page's content whenever required. For example, you have to show f 100 images on a single web pa; initially, users can see only 10 images, and users need to scroll the web page to see other images. In such cases, we can initially load the first 10 images and other images whenever the user scrolls the web page.

In this way, we can use the lazy loading technique to improve web page performance.

Prioritize Content of Web Page

Another approach for progressive rendering is by prioritizing the required content. For example, while loading the web page, we can initially show the intractable part of the content first, and after that, we can load the other content.

Also, we can render only the required CSS initially. For example, we need to fetch data from API, and after that, we require to render the data. So, if we render all CSS together, it also renders the CSS for unfounded data, which we can render after fetching data.

So, in this way, we can show the content with high priority initially, and after that, we can show other content on the web page.

Why Should Developers use Progressive Rendering?

Here we have explained some advantages of progressive rendering.

Faster Web Page Loading

The main benefit of progressive rendering is that it increases the web page's speed. It loads the web page's content in chunks so users can start interacting with the web pages immediately when they open the web page.

Improved User Experience

As progressive rendering increases the website's loading speed, users can engage more with websites. It also increases the number of visitors of the website.

Improved SEO of the Website

In SEO, web page speed is one of the important features. Google’s crawler bot crawls through every page and evaluates the website's content. If the loading speed is low, the crawler bot can skip the web page, and if the web page speed is less than 1 second, it ranks the website between competitors.


Progressive rendering is a technique to improve the performance of the web page by rendering the HTML, CSS, and JavaScript content of the web page in smaller chunks or whenever required. We have also discussed two ways to achieve progressive renders and the benefits of using progressive rendering.

Updated on: 27-Apr-2023


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