Image Optimization: What Is It and Why Is It Important?
Tags: webdev, beginners, productivity
Published: 2022-01-07 14:45:37



**Optimizing your images for performance has a lot of benefits.** You can optimize your images by using best practices to keep your file size small and your site loading quicker, resulting in a better user experience. There’s another reason why image optimization matters, and it’s directly related to profit. Images take up a lot of disk space on the server that runs your site and slows it down.
While it’s not the end of the world if you exceed that limit, you may get charged an overage fee or possibly — have your website shut down. You can make the most of your site storage and avoid the bandwidth limit by optimizing your images.

**Image optimization benefits include:**

*Reduced bounce rate — if you load fast, users are more likely to stick around

*Better customer engagement — images make a big difference in the user experience. Web visitors are less likely to engage with a website that loads slowly (even if the rest of the content is visible).

*Save on hosting and content delivery by optimizing images. Bandwidth is expensive, and by using less, websites use less.

*A better search ranking — Google and other search engines look at the page load time and performance. Optimizing images can boost rankings and traffic.


**Techniques for Image Optimization**

Pick the right file type
First, choose the right file type for your image. 
_The most commonly used types are:_

*PNGs make great images but are a lot bigger. PNG can be configured to enable lossy compression, but it’s lossless by default.

*With JPEGs, you can balance quality and file size by adjusting the quality level, which ranges from 1–100%.

*The GIF format supports only 256 colors and compression is lossless. More popular for animations than static images.

Use NextGen JPEGs and Progressive JPEGs.

**A JPEG image can be rendered in two ways:**

*Baseline loading — display the images in full, from top to bottom. It can be a bit of a pain if your internet is slow.

*Gradual loading — initially showing a low-quality image, then improving it as more of it loads.

You can improve your website or app’s performance for users with slow Internet connections by using progressive JPEG.

Another way to speed things up is with next-generation formats like WebP and JPEG-XR. With these image formats, you can save a lot of space without sacrificing quality. Google’s website optimization guidelines recommend them, so they’re important for SEO too.

There’s an issue with next-generation formats that they’re not supported by all browsers, so you need to prepare a fallback image (like PNG) to use if the user’s browser doesn’t support them.

**Caching**

Caching involves storing images in a proxy server or browser cache, to make it faster to serve content. Using browser caching can reduce application requests and downloads.

For a proxy server to cache image files, several points of presence (PoP) servers must be configured across the globe. It speeds up page load times because images are served from the closest server If you use an image caching service, you’ll get cached images. 

Image caching services preprocess images before caching them so they load faster. This is great if you are using low-performance formats and static images.

**Compression**

A compression technique reduces the size of an image. There are lossy and lossless compressions.

*Lossy compression reduces file size by getting rid of redundant data. Although this can reduce image file size, it also degrades quality. You can’t undo the compression. Keep a copy of everything you do.

*Lossless compression maximizes quality above size. Using this technique will preserve the file’s quality so that you can restore it later. It won’t reduce the file size much, though.

**Resizing**

Although the image cannot be compressed completely, the size and resolution still have to be balanced. As the resolution increases, the file size increases. Web pages load slower when high-resolution images are used. If a visitor accesses your website using a mobile device, his or her bandwidth is likely to be limited, which means large images will likely take longer to load.

It is best to strike a balance between image quality and file size. Sizing the image to the smallest size that will still produce the desired visual effect is the best solution. You can also show a thumbnail if you need to display large high-resolution images and download the full image when the user asks for it.


**Optimize your image delivery!**

It doesn’t matter if your image is optimized by following the steps above. You can improve it further. Images load fast for your users based on server speed and network performance.

Get your image server ready for spikes in traffic and handle three to four times as much traffic as normal. Cached images should always have a cache header so local devices can use them.

Alternatively, you can use a Content Delivery Network. You can get your images to users closer to their locations with a CDN. Your images will load faster on nearby servers. They’re easy to set up and are a great solution for improving image performance.

**Try loading lower quality images with the Blur method**

The speed of your site can still slow down if you have large file sizes or lots of images, even after all the previous optimization steps. Trying to optimize not just images but also load times can make visitors think your site is loading faster.

Let’s make it look like your photos are loading faster so your users don’t just stare at a blank page.
Load a Lower Quality Image (LQI) for this. It’ll show a smaller version of the image while it loads, so you can look at it while you wait. This makes it look like the page loads faster, even though everything is loading just as fast.
**
Use lazy loading to load your images.**

One more trick you can use to give the impression that images are loading faster: Lazy loading. You start at the top of the page when someone lands on your site. 
They’ll probably scroll the whole thing, especially if they’re engaged. Rather than loading all the images at once, lazy loading relies on the assumption that users care most about what they can see. 

As a result, the images inside their browser view have a full load first, while the rest load a placeholder until the user scrolls over to that area of the page.