Lazy Loading Explained: What It Is and Why Your Website Needs It
Ever felt stunned looking at a website? There are many websites that have beautiful visuals, quality images, animations, sliders and user friendly sections. Website design catches the user’s attention, but it can also make the site heavy. This is where lazy loading your website helps.
Some studies suggest that around 16% of webpages lazy load the hero image as of 2024. A heavy website becomes slow and people have to wait after every click.
Some people wait a few seconds, but many will leave the website quickly if it takes longer. Sometimes the solution is as easy as lazy loading your website. Slow website makes you lose website visitors, trust, search ranking and sales. No business wants it, right?
There are multiple benefits of lazy loading, which is why many business owners have already started implementing it. It looks simple but can affect the website efficiency.
The first page of the website should be fast. It helps people stay longer, save data and keep the website smooth and fast, especially on phones.
In this blog, we will cover:
Websites lazy load their content so that a visitor can find the content on the screen first. Other things, like images down the page or videos at the bottom, do not load right away.
When the visitor scrolls and gets closer to those parts, only then the website loads them. This way, people do not have to wait for the content they want to see on your website.
So, when you lazy load content on your website, it is like loading the page in steps. It shows the visitor the top part first. Then it keeps loading the rest as the visitor moves down.
Lazy loading is the opposite of eager loading. Eager loading tries to load everything at once. It loads all images, all scripts, all videos and all page sections at the start. That makes the first load heavy.
Lazy loading on the other hand tries to be smarter. It adjusts according to what is needed now and what can wait.
Online shops have product photos, review sections, popups and tracking scripts. Blogs have images, ads and embedded videos. These all add weight.
Therefore, when a user opens a page, the browser starts downloading many things. If it downloads too much at the same time, the page becomes slow.
When you lazy load your website, it helps by reducing the amount of data downloaded first. It reduces the number of requests sent to the server at once. It also reduces how much code runs at the start. All these small reductions can make a big difference.
When you lazy load content on your website, it is not just a ‘trick’. It is one of the effective strategies for modern websites. It is a way to respect the visitor’s time and data.
Some studies suggest that around 16% of webpages lazy load the hero image as of 2024. A heavy website becomes slow and people have to wait after every click.
Some people wait a few seconds, but many will leave the website quickly if it takes longer. Sometimes the solution is as easy as lazy loading your website. Slow website makes you lose website visitors, trust, search ranking and sales. No business wants it, right?
There are multiple benefits of lazy loading, which is why many business owners have already started implementing it. It looks simple but can affect the website efficiency.
The first page of the website should be fast. It helps people stay longer, save data and keep the website smooth and fast, especially on phones.
In this blog, we will cover:
- What lazy loading is and why it matters
- Common methods and how to implement it
- Does lazy loading affect SEO
- What to lazy load and what not to lazy load
- Common mistakes and why it matters to lazy load your website
What Is Lazy Loading
Lazy loading means loading content only when it is needed.Websites lazy load their content so that a visitor can find the content on the screen first. Other things, like images down the page or videos at the bottom, do not load right away.
When the visitor scrolls and gets closer to those parts, only then the website loads them. This way, people do not have to wait for the content they want to see on your website.
So, when you lazy load content on your website, it is like loading the page in steps. It shows the visitor the top part first. Then it keeps loading the rest as the visitor moves down.
Lazy loading is the opposite of eager loading. Eager loading tries to load everything at once. It loads all images, all scripts, all videos and all page sections at the start. That makes the first load heavy.
Lazy loading on the other hand tries to be smarter. It adjusts according to what is needed now and what can wait.
Why Do You Need Lazy Loading
Modern websites are not lightweight anymore. Even a simple business website can have many images, icons, fonts and scripts.Online shops have product photos, review sections, popups and tracking scripts. Blogs have images, ads and embedded videos. These all add weight.
Therefore, when a user opens a page, the browser starts downloading many things. If it downloads too much at the same time, the page becomes slow.
When you lazy load your website, it helps by reducing the amount of data downloaded first. It reduces the number of requests sent to the server at once. It also reduces how much code runs at the start. All these small reductions can make a big difference.
When you lazy load content on your website, it is not just a ‘trick’. It is one of the effective strategies for modern websites. It is a way to respect the visitor’s time and data.
Is Lazy Loading Only for Images
Many people think the benefits of lazy loading are only for images. But it can be used in multiple ways as shown in this table:
Common Ways to Do Lazy Loading
When you lazy load your website, it usually works with the idea of the viewport. The viewport is the visible area of the screen.An image outside the viewport is not visible first. When you lazy load web content, the browser does not load it until the visitor scrolls close to it.
Many times, when you lazy load, it shows a placeholder first. A placeholder can be a blank space or a blurred small image. This helps the page keep its shape while the real image is not loaded yet. When the real image loads, it replaces the placeholder.
There are two common ways to lazy load your website as shared in the table:
Key Point: It’s simple to lazy load your website. Just prioritise what users see first and delay the rest.
Here are the biggest reasons why you need to lazy load your website.
The above-the-fold content should load fast and the below-the-fold content should load later. This can improve performance scores like Core Web Vitals. CWV is about how fast the main content shows on your website.
However, visitors want to get the information quickly. Even if the full page takes longer, it is fine if the top part appears fast. When you lazy load content on your website, it helps exactly in this part. It makes the initial load lighter.
When you lazy load your website, it helps mobile visitors a lot because it reduces the amount of data loaded at the start. It also reduces CPU work. The page becomes smoother. It makes it easy for the visitor to read the first part without waiting for everything to download.
This matters because mobile visitors often want quick answers. When you lazy load content on your website, it helps meet that need.
When you lazy load your website, it prevents loading content that the visitor never sees. Many people do not scroll to the bottom of a page. If a website loads 30 images but the visitor only sees 10, then 20 images were loaded for no reason. When you lazy load, it helps you prevent this.
It reduces server load because fewer requests happen at one time.
Instead of a big storm of requests at page start, the requests are spread as the user scrolls. This can help the server stay more stable, especially when many users visit the site at once.
So, a safe approach is:
Why Your Website Needs Lazy Loading
When you lazy load your website, it is not only about speed. It is also about experience, comfort and trust. When a website loads fast, people feel calmer. It feels professional and safe.Here are the biggest reasons why you need to lazy load your website.
1. Faster First Load
If a large hero image is delayed by mistake, it can hurt the score. But if it is used correctly, there are multiple benefits of lazy loading.The above-the-fold content should load fast and the below-the-fold content should load later. This can improve performance scores like Core Web Vitals. CWV is about how fast the main content shows on your website.
2. Better Page Speed
When a web page loads, the first few seconds matter the most. Good speed makes a website efficient and easy to use. If buttons on the site take time to respond and images load too late, it affects the overall user experience.However, visitors want to get the information quickly. Even if the full page takes longer, it is fine if the top part appears fast. When you lazy load content on your website, it helps exactly in this part. It makes the initial load lighter.
3. Better Mobile User Experience
Many people visit websites on phones. Phones often have slower internet, smaller screens, limited power and memory.When you lazy load your website, it helps mobile visitors a lot because it reduces the amount of data loaded at the start. It also reduces CPU work. The page becomes smoother. It makes it easy for the visitor to read the first part without waiting for everything to download.
This matters because mobile visitors often want quick answers. When you lazy load content on your website, it helps meet that need.
4. Lower Data Use
When a website loads everything at once, it uses more data. This is not friendly for visitors who use mobile data plans. It can also be costly for the website owner because it increases server bandwidth use.When you lazy load your website, it prevents loading content that the visitor never sees. Many people do not scroll to the bottom of a page. If a website loads 30 images but the visitor only sees 10, then 20 images were loaded for no reason. When you lazy load, it helps you prevent this.
5. Lower Server Load
A slow website feels stressful. Many people connect slow speed with low quality, even if it is not true. So when you lazy load content on your website, it supports the feeling of a good website.It reduces server load because fewer requests happen at one time.
Instead of a big storm of requests at page start, the requests are spread as the user scrolls. This can help the server stay more stable, especially when many users visit the site at once.
6. SEO Benefits of Lazy Loading
When you lazy load content on your website, it can support SEO because it can improve speed and speed is important. It can also reduce server work and make the site more stable. But SEO needs content to be accessible as well.So, a safe approach is:
- Keep main content in HTML and load it normally
- Lazy load only extra media like below fold images and embeds
- Make sure images still have proper alt text
- Make sure the code does not hide content from search engines
- Make sure the page still renders well without heavy scripts
Does Lazy Loading Affect SEO
Search engines care about speed and user experience. A fast website usually ranks better. When you lazy load, it can help a website become faster and it supports SEO.Also, when a website loads too slowly, people leave quickly. That can increase the bounce rate. Even if bounce rate is not a direct ranking factor in a simple way, user signals still matter in different ways. A better experience often means better results.
A lot of people have this question: does lazy loading affect SEO? The answer is yes, therefore, it must be done carefully for SEO.
If important content is lazy loaded wrongly, search engines might not see it properly. Also, if images are lazy loaded without correct attributes, it can impact image SEO. So, when you lazy load content on your website, it is good but it needs the correct setup.
SEO plays a crucial role in the success of a website. If you want to learn more about SEO, read NAP & Local SEO: The Power of Accurate Info.
What Should Be Lazy Loaded
The best way to start is to think like a visitor. A visitor opens the page and looks at the top. So anything that is not needed in the first screen can be delayed.Here are the most common things that should be lazy loaded.
1. Images Below the Fold
This is the most popular use. Blog images, gallery images, product images and long landing page images are perfect to be lazy loaded.2. Videos and Heavy Media
Videos are heavy and can slow down the page a lot. A better way is to show a thumbnail first. Then load the video only when a visitor clicks play or scrolls close to that section.3. Iframes like Maps and Embeds
A YouTube or Google Maps embed can load extra third-party JavaScript and network requests in the background. That is why it is better to load them only when needed.4. Ads and Third Party Widgets
Many websites use ads, chat widgets and other third party tools. Some of them are not needed to your visitors at first. When you lazy load content on your website, it can help them start later, when the page is already stable.5. Extra Page Sections
Some page sections are helpful but not needed at start, like reviews, comments, related posts and extra product detail blocks. These can load later or load after a visitor scrolls near them.6. Non Critical JavaScript and CSS
Some third-party scripts are only needed for specific sections. For example, a library that runs an animation at the bottom of the page. Or a script that is needed only on one page, not all pages of the site. These can be delayed. Some CSS for special effects can also be delayed.When you lazy load a website, it is not only a tool. It is like a mindset. It is asking one question: does this need to load right now or can it wait?
What Should Not Be Lazy Loaded
While you do lazy load your website, you should know that some content should not be lazy loaded. They help the visitor to decide if the page is useful or not.Here are the most common things that should not be lazy loaded.
1. Hero Image and Main Headline
If the top image or headline is lazy loaded, the page looks empty and slow. This can hurt performance scores like the LCP of a website. It also makes the website feel broken.2. Logo and Navigation
The menu and logo are not unnecessary. They help visitors explore and trust the website. If a menu loads late, your visitors may feel lost.3. Main Call to Action Buttons
Buttons like Book Now, Buy Now, Get Quote or Contact should appear fast. If they load late, the visitor may leave before they even see them.4. Critical CSS and Main Layout Styles
If the main CSS is lazy loaded, the page can show without styling for a moment. This is not a good gesture. It is called flash of unstyled content. It feels cheap and confusing. The main styles must load first so the page looks stable.Thus, when you lazy load, it is not about lazy loading everything. It is about choosing what is safe to lazy load.
How to Implement Lazy Loading
Some website owners want a very easy solution. Others want full control. Both ways can work, depending on the website.1. Native Lazy Loading in HTML
Modern browsers support a simple option for images and iframes. Adding loading=”lazy” can make the browser delay the loading. This is very simple and does not need third-party scripts or plugins. It is also safer because the browser handles it.This method is good for many websites, especially small and medium sites.
2. JavaScript With Viewport Detection
Some websites need more control. For example, background images in CSS cannot always use the simple HTML attribute. Also, some websites want to load whole components only when they are needed. JavaScript can do this.A common modern method is IntersectionObserver. It watches when an element is close to the viewport. When it is close, then it loads.
This method is powerful. But it must be written properly, because inefficient scripts can also slow down the page.
3. Using Tools and Plugins
Many websites use WordPress. WordPress lazy loads the images by default in newer versions. Also, plugins can help lazy load images, videos and iframes. Some performance tools also provide automatic ways to lazy load.This is good for people who don’t want to edit code. But it still needs testing. Not every plugin works perfectly with every theme. Some aggressive tools can break parts of the website or delay things too much.
So even when using plugins, testing matters.
What to Test When You Lazy Load
When you lazy load content on your website, it changes how the website behaves. It changes when things load and sometimes how they load.This table represents testing checklist for your website:
A website can look fine on one device but broken on another. A browser can support one method but not another. That is why you should always test when you lazy load a website.
The fix is simple. Above the fold content should load normally. Only below the fold should be lazy loaded. Critical content needs priority.
The fix is to set width and height for images and iframes or use aspect ratio in CSS. Using placeholders or blurred low quality images can help the layout stay stable.
A stable layout feels peaceful. A jumping page feels stressful.
The fix is to separate critical and non critical resources. Critical CSS and main scripts that control navigation or layout should load first. Only non-critical scripts should be lazy loaded.
When you lazy load a website, it is about finding the right balance of what can be delayed.
The fix is to defer the content carefully and load only when it is needed. It helps to use lighter alternatives or reduce the number of third party tools.
A website should not feel like a busy market of scripts. It should feel clean and focused.
The fix is to exclude these elements when you lazy load or use a different way. For example, load the carousel images when the page loads or load tab content when the tab is clicked.
Common Mistakes of Lazy Loading
When you lazy load content on your website, it is helpful but mistakes are common. These mistakes can reduce performance instead of improving it.1. Lazy Loading Above the Fold Content
This is the most harmful mistake. When the hero image or main content is lazy loaded, the page opens and looks empty. The visitor waits again. Performance metrics become worse, especially Largest Contentful Paint. This makes the website look like it is failing.The fix is simple. Above the fold content should load normally. Only below the fold should be lazy loaded. Critical content needs priority.
2. Not Reserving Space for Images and Videos
When an image loads later and there is no reserved space, the layout shifts. Text jumps. Buttons move. This can cause bad user experience. It also affects CLS, which is an important performance score.The fix is to set width and height for images and iframes or use aspect ratio in CSS. Using placeholders or blurred low quality images can help the layout stay stable.
A stable layout feels peaceful. A jumping page feels stressful.
3. Lazy Loading Too Many Scripts and Styles
Some people get too excited and try to lazy load many JavaScript and CSS files. But some scripts and styles are needed for the page to look and work correctly. If they are delayed, the page can break or show without styling or become hard to use.The fix is to separate critical and non critical resources. Critical CSS and main scripts that control navigation or layout should load first. Only non-critical scripts should be lazy loaded.
When you lazy load a website, it is about finding the right balance of what can be delayed.
4. Lazy Loading Third Party Content Without Control
Third party content can be heavy. Ads, tracking, chat widgets and social embeds often slow down a website. When you lazy load, it can help but sometimes they load in inappropriate ways. They may fail and leave empty boxes.The fix is to defer the content carefully and load only when it is needed. It helps to use lighter alternatives or reduce the number of third party tools.
A website should not feel like a busy market of scripts. It should feel clean and focused.
5. Lazy Loading Non Scrollable Items
When you lazy load content on your website, it works when things enter the viewport. But some items do not enter the viewport in a normal way. These can be content inside a carousel, content inside a fixed container or special tabs. These can fail to load properly when you lazy load a website.The fix is to exclude these elements when you lazy load or use a different way. For example, load the carousel images when the page loads or load tab content when the tab is clicked.
Why Lazy Loading Matters
When you lazy load content on your website, it is not only a technical thing. It is also about:- Showing kindness to the visitor
- Respecting user’s time
- Understanding data plans
- Understanding slower phones and internet
- Making the experience smoother
Additionally, it also supports business goals. When pages load faster, more visitors stay on your site. When more visitors stay, more of them read, click and contact. When the site feels smooth, trust grows. And when trust grows, results get better.
Conclusion
When you lazy load a website, it looks simple. Yet, it has a huge impact on your website. It is a powerful method to delay showing the content until your user needs it. This reduces the website weight, improves the loading speed and gives your users a better experience.Most people use their phones for education and learning. When you lazy load content on your website, it is a great way to save bandwidth and help them enjoy fast loading information.
When done right, the benefits of lazy loading are undeniable. It can make your website feel:
- Safer, reliable and faster
- Stable, cleaner and smoother
- Stronger and more responsive
- Human friendly and professional
- Respectful of the user’s time
When you lazy load content on your website, it is not a trend. It is a smart strategy many modern websites use. If you want to give your users a smooth experience, contact us today.
Is the website loading slow even when the design is good?
Lazy loading can speed it up without removing content, but it must be set up the right way. Speak to our Website Maintenance team today to get a quick check to fix above-the-fold loading and stop layout jumps.
Faqs
Lazy loading is a website loading method where non-essential content loads later, only when it is needed. Instead of loading every image, video, and embed at the same time, the page loads the visible content first and delays the rest until a visitor scrolls near it. It is used because it makes the first view of a page faster, saves data for mobile users, reduces server pressure, and keeps the browsing experience smoother.
Yes, lazy loading can improve a website score in speed tools because it reduces the amount of work the browser must do at the start. When fewer heavy items load on the first screen, the page often loads quicker and looks faster. This can improve performance scores, especially when long pages have many images, videos, or embeds. The key is correct setup, because delaying the wrong elements can lower the score instead of improving it.
Lazy loading is good for SEO when it is done correctly. Search engines prefer fast, stable pages because users stay longer and interact more. Lazy loading can support better speed and smoother experience, which can help SEO outcomes. But it should not delay important content at the top of the page, and images should still have proper descriptions so search engines can understand them. When lazy loading is clean and careful, it usually supports SEO rather than harming it.
The main benefit of lazy loading images is faster initial page loading. Only the images that a visitor can see at the start load first. Images further down the page wait until the visitor scrolls. This saves time, reduces early data usage, and avoids loading images that the visitor may never reach. It also helps mobile users, where heavy images often cause the biggest slowdowns.
Lazy loading a website means applying the same idea beyond images. It means loading the page in a smart order, so essential content loads first and extra content loads later. This can include videos, iframes like maps or YouTube embeds, third-party tools, and non-critical scripts used for features that appear later on the page. The goal is to make the first experience fast and stable, while still keeping the full content available when the visitor needs it.
A simple example is a long blog page with many images. With lazy loading, only the images near the top load when the page opens. The images in the middle and bottom stay unloaded until the visitor scrolls down. Another example is a page with an embedded map or video near the bottom. Instead of loading that embed immediately, the page loads it only when the visitor reaches that section. The visitor still gets the full content, but the first load becomes lighter and faster.
Yes, lazy loading can improve website performance because it reduces initial page weight and spreads loading over time. It lowers the number of heavy downloads at the start and can reduce how much the browser has to process immediately. This often makes the page feel quicker, smoother, and more stable. It can also reduce wasted loading, because many visitors do not scroll to the end of a page, so delayed resources may never need to load at all.
Lazy loading images can be created by using a built-in browser option where supported, or by using a scroll-based method that loads images only when they come near the visible screen. Many website platforms also provide lazy loading through settings or performance plugins. The most important part is choosing the right images to delay. Images that appear at the top of the page should load immediately, while images further down can be delayed. Also, space should be reserved for each image so the page does not jump when the image loads, because that jump harms the experience and can reduce performance scores.