The main purpose of image formatting should be lowering the file size of an image in such a way that an acceptable standard of quality can be maintained. Image optimization can be achieved in more than one way. The easiest way to optimize would be to compress your files before uploading them. This can usually be done using compression tools. Some optimization tasks can also be accomplished using plugins.

• Choose the right combination of file format and compression type—

Two things are extremely important for image optimization— the file format and the type of compression you intend to use. You can reduce the size of your images considerably by choosing the right combination of file format and compression type. However, to find the best combination, you will need to play around with the two determinants.

• Choosing the most appropriate file format—

Before you begin to modify your images, ensure that you have the right file type. There are many file types you can choose from. Here are some of the most common ones—

PNG – 

Although PNG Files are large in size, they feature good quality. Yes, the PNG format was created to be lossless, but it can be lossy.

JPEG –

JPEG can be used for both lossless and lossy optimization. To strike a good balance between file size and quality, tuning the quality level would be a great idea.

GIF – 

GIF makes use of just 256 colours. Ideal for animated images, GIF uses only lossless compression.

WebP and JPEG XR are among the other image file formats used. However, not every browser supports these. So, while you can use PNG for images that are simple, JPG or JPEG should be used for images that feature a lot of colours.

Choosing the most appropriate compression rate—

The first option is to use a low compression rate which produces the best quality but larger files. The second option is to use a very high compression rate, which results in a lower-quality image but a smaller file size. 

It’s best to keep a webpage’s weight below 1 or 2 megabytes. And to achieve that, you will have to find such values for compression rate (quality) and file size that would ensure good quality output with an acceptable file size. Ideally, PNGs and simpler images should not exceed 100 KB.

It’s recommended to use lossless compression when compressing photographs or images with high quality. For tutorial screenshots, you can also go for lossy compression to get the largest size savings.

• Scale down your images according to your website’s needs—

Resizing images is extremely important to decrease the load time of your site. Resizing should be done precisely based on the requirements of your website. We are not pointing at the resizing that is done at the HTML and CSS levels. We are instead talking about image resizing done on the server, the output of which can then be sent to the browser.

Say, you have a 4000x3000px image. But you need a smaller version of this image on your site. So, what you need to do is scale the original image down to the new size you need and then send it to the browser. Images that have been resized are lighter and, hence, load faster.

• Have a responsive website—

A responsive website is a site that adjusts its layout according to the size of the device in which it is being viewed. Responsive websites load on desktops as well as mobile devices without hassle.

You can use responsive images on responsive websites/ sites that are both mobile and desktop friendly. You can use responsive image tags to provide the browser with a list or variants of an image for different screens. It’s then the job of the browser to determine which image size would be the most appropriate to load on a device as per its dimensions.

• Strategic loading of images—

It’s not a great idea to have a lot of images on your website, even if you have optimized them all. When multiple images load at the same time, the load time of your website increases and user experience dips. If however, you can’t remove images from your site probably because they are extremely important, you can use a technique known as lazy loading. Lazy loading means deferring image loading to prevent a site from slowing down. The images can load later when they are about to enter or have entered the user’s viewpoint.

Now, a solution to make both image-heavy and video-heavy websites load faster—

• Leveraging the power of CDN—

CDN, also referred to as Content Delivery Network, is a server network that caches copies of all the assets on a site. CDNs are able to resolve redundancy issues and speed up content delivery as they serve content using edge servers closest to users. This is crucial for serving large files like heavy images and videos. This way, users don’t need to wait for images and videos to download or to buffer.

Meaning, a CDN can dramatically improve the performance of your website.

Even though the tips dished out above may seem small, anything that can reduce load time by even one second is worth doing. Remember, load time can make a big difference in your site’s conversions and success.