What Is Image Optimization and Why Is it Important for SEO?

Image Optimization

Last updated - July 8, 2021

Visual content is integral to every website nowadays, with more than 80% of marketers using rich media for digital campaigns. The last update in Google’s image search interface has raised visual content importance in page ranking even more. Optimizing the images reduces page load speed and improves significantly the page ranking. Read on to learn more about what is image optimization and why it is important for SEO. 

What Is Image Optimization?

Image optimization refers to the process of delivering high-quality images while keeping the smallest possible size. 

There are three main methods for image optimization: resizing, caching or compressing. Resizing means to reduce the size of the image to achieve the smallest size with the highest quality. The caching method, stores image files within the browser cache, reducing the page load time.

Why Is It Important to Optimize Images?

Every day, according to Google, hundreds of millions of people use Google Images to search for web content visually. Image search represents 27% of all queries generated across the top 10 US web search properties. 

The updating of Google’s “View Image” button from Image Search to “Visit [Page].” resulted in analytics platforms recording an increase in sessions generated from image search. This increased content visibility for the host pages.  Images are an important source of traffic and we should take advantage of it. 

Optimizing your images reduce the page load times. Therefore, there are more chances visitors will stay at your website, since the average time a user waits for a page to load in 2 seconds. The quicker your page loads, the higher your visitors’ permanence on site. Moreover, because Google is prioritizing faster sites, and penalizing slow sites. In summary, optimizing your images can help you with two key aspects:

Page load speed

Images contain more than half the weight of webpages. That is why optimizing the image sizes is the simplest way to minimize your load speed.

SEO Ranking

Achieving the golden left corner is the goal if every marketer and web administrator. Therefore, optimizing the images for SEO is a must. We will cover some tips and techniques in the following section. 

The Case for eCommerce

Optimizing images is especially important in the case of eCommerce stores to provide a clear and engaging catalog. That being said, you need a solid eCommerce platform that has built-in SEO features to rank higher in search engine results. 

The three top eCommerce platforms, Shopify, Magento, and Woocomerce, stress the importance of optimizing images for SEO. For example,  Shopify has an online tutorial where it recommends to its users to optimize their images for SEO and conversion, preferring JPG files over other formats due to the ratio of quality and size. 

Therefore, choosing the platform that provides the best SEO functionality is key to maximize the impact of your optimized images. Let’s quickly review those three top eCommerce platforms:


Provides access to the source code of your store and has an array of customizations available, therefore it is considered SEO-Friendly.  An extension to the WordPress content management system is therefore compatible with WordPress SEO plugins. It is one of the most popular eCcommerce platforms, according to this statistic

Some of the SEO plugins available for WooCommerce are: 

  • MonsterInsights
  • All in one SEO pack
  • Google XML Sitemaps
  • W3 Total Cache
  • BZ Lazy Load
  • SEO Optimized Images

Pricing—it is a free eCommerce plugin with free updates, offering priced extensions for SEO starting from $49

Security—you should install an SSL certificate sold by the host or a third-party vendor, requiring strong passwords, and limited logins. 

Performance—WooCommerce tends to get slower when loading images with a large number of versions.


An end-to-end managed eCommerce platform, one of the most widely used platforms. 

SEO—Provides strong SEO built-in features that can be extended for medium and large online stores. Some of the SEO extensions available for Magento are: 

  • Magento SEO Suite Pro extension v9.5.2
  • Advanced SEO Suite by Mirasvit
  • Free Magento SEO Extension by Creare
  • Ultimate SEO Suite by AheadWorks v1.3.8

Pricing—it is open-source, with a free community edition. Magento Enterprise Edition is the paid version, with pricing by requesting quote. Like WooComerce, offers paid SEO extensions.

Performance—it functions as a Content Management System, and being backed by Adobe, it makes them agile and user-friendly. 


A cloud-based eCommerce platform, the no-limit sell feature makes it highly popular. 

SEO—Shopify Apps are like plugins to extend its functionalities, with its own marketplace for apps. 

Some of the best SEO Apps for Shopify include:

  • SEO Image Optimizer
  • SEO Meta Manager
  • Ultra SEO

Pricing—comes with different pricing plans, starting with a 14-day trial. The basic plan starts from $29 and goes up to $279. 

Performance—One of the best features of Shopify is the high loading speed for pages. This is the result of the high priority Shopify puts on image optimization. 

How To Optimize Images for Web and Performance

Here are some tips to help you optimize your images for best performance.

#1. Naturally naming image files

The simplest way to include images in your SEO is to name them. Try to find the logical name for images, using the keywords the image could rank for. 

For example, let’s say you have an e-commerce store selling hand made jewelry and you are selling the earrings in the image below, which you named “ Silver Blanket”: 

You can name the picture “image17797.jpg” or you can name it “earrings-seed-beads-woven.jpg”, more according to the search keywords your potential customers can use to look for your products. 

Similarly, images alt and title attributes help images rank higher in searches, improving user experience. This, in turn, builds the page relevance over time, resulting in the search engine identifying the page as a page worthy of ranking higher. 

Write those attributes concisely and grammatically logic to help accessibility readers, thus improving all users’ experience. The same applies to on-page image captions and keywords surrounding the image help search engines to get more context for images.

The host page’s HTML title tags are now displayed in image search results, so these should be relevant to the image as well.

#2. Using the right size and format

Working with different kinds of formats can help you to keep your website weight on track. For example, you can use SVG for logos or icons since it is light and works well with simple images and limited colors. 

PNG is great to use with images with a transparent background, although it is the heaviest type, so use it sparingly. JPG is the most commonly used image type since it allows for a lot of detail and colors. However, you should keep JPG images lighter than 100 KB and 1920 px to avoid adding too much weight to the page.

If you need to save a large image, you can set it as progressive JPG, where images start displaying progressively as they are loaded

GIFs should be saved for simple animations with simple color schemes as they are limited to 256 colors. 

#3. A/B test your images

A great example of how to improve your images is the Unilever case. Unilever revolutionized the market with their hero images in place of the traditional pack-shots to improve the mobile user’s experience. This hero images convey more information, with a close up of the package and a strip showcasing the elements of most interest to a consumer. 

#4. Hosting and caching images

Images can increase the number of requests made to the server before the browser can finish loading the page, slowing down the page.

Image sprites and hosted images were useful once to speed up retrieving and loading images Today, depending on your setup, it may be faster to host images on the same host as your HTML files.

Hosting images on your domain help to capture potential link equity from any embedding your images into their content. Other benefits include controlling the cache,  branding, and control of redirects. 

Using a Content Delivery Network (CDN) can shorten load times by having the server close to the user location. 

Regarding caching. images should be the assets with the longest caching times, setting server expirations for all image types.

When it comes to caching, also make sure that server expirations are set for all image types. Images should be some of the resources with the longest caching times (usually many weeks).

#5. Using a digital asset management solution

A digital asset management solution can help not only to organize your image library but with image optimization too. A good DAM solution has automated tagging, helping you to manage properly naming your images with the right, searchable keyword.

#6. Use lazy loading

According to how you load your images, you can actually slow your pages. Using the lazy loading technique allows the page to finish loading despite having off-screen images loading when a visitor scrolls down the page.

This can improve page speed but you should be careful to index the images properly. For that matter, using image sitemaps help with indexing, thus boosting discovery and crawling. 

You can learn more about how to optimize your images for eCommerce sites such as Shopify or WooComerce in this YouTube tutorial.

In Sum: Use Images to Boost Your SEO

Images are not only nice visual aids to your content. Nowadays, images actually drive traffic to your content, having the potential to build permanence and boost your page rank. Therefore, optimizing your images to attract searches is a must for every website willing to improve its SEO. 


Please enter your comment!
Please enter your name here