How to optimize images for SEO



In the previous article, we talked about how to optimize texts from an SEO perspective. In order to optimize the articles in the best way one of the fundamental points is use and optimize images for SEO.

So if you’re wondering if your article needs an image the answer is always Yes. As well as contributing from an SEO perspective, images complement the article.

Let’s look at how to fully optimize images for SEO and how to use them to improve the user experience.

Always use images

Images, when used properly, help readers to better understand your article. They serve, in fact, to revive and strengthen the concept you want to express, for example you can put in an infographic.

In addition to that visual search is becoming more and more important, so. your images could bring more traffic to the site. In fact, Google Images has a new interface with new filters that show that Google knows more and more about what’s in an image and how it fits into context.

How to optimize images for SEO

Find the right image

Find an image relevant is essential. The image must reflect the topic of the post or have illustrative purposes within the article. In addition, it must be placed near the text related. An image with related text will rank better for the keyword it is optimized for.

Even better if the image is original and not stock. If you don’t have original images that you can use, there are other ways to find unique images. We, for example, really like the images provided by Unsplash.

Prepare images for use

Once you have found the right images (photos, illustrations or graphics), the next step is toto optimize them for SEO. So before you add your images, there are a number of things you need to think about:

1. Choose a file name

The file name should never be generic such as ABC456.jpg. A correct file name, in our case, could be optimization-seo-images.jpg. Do you want Google to know what the image is about without even looking at it? Use the key phrase in the filename.

2. Choose the right format

The format depends on the type of image and how you want to use it, we recommend you choose:

  • JPG: for large photos or illustrations. It will give you good results in terms of color and clarity with a relatively small file size;
  • PNG: if you want to keep the transparency of the background in your image;
  • WebP: to get high quality results with smaller file sizes;
  • SVG: for logos and icons.

3. Resize images

Loading times are important for UX and SEO. The faster the site, the easier it is for users and search engines to visit and index a page.

Images may have a great impact on loading times, especially if you upload a very large image and then display it at a very small size. For example, a 1920×640px image displayed at a size of 150×150px will slow down the page as the entire image will take longer to load.

So the best thing to do is resize the image to the exact size you want it to be displayed at. WordPress helps you with this. Once the image is uploaded it comes in three sizes: large, medium and thumbnail. Unfortunately, this doesn’t mean that the file size is optimized as well, only the display size of the image is.

4. Reduce the file size

The next step in optimizing your images for SEO should be to make sure your resized image is compressed. This way the published photo will have the smallest possible file size.

It is preferable to use images of the the highest possible qualityas many devices now use retina screens. You can still reduce the file size by removing the EXIF data. We recommend using tools like ImageOptim or sites like Squoosh, JPEGmini, or

After optimizing your images, you can test your page with tools like Google PageSpeed Insights, Lighthouse, or Pingdom. Our favorite is Lighthouse because it also provides us with Web Vitals scores.

Add images to your article

Now your images are ready to use. As mentioned earlier, adding a photo, next to its related textual content, helps a lot in terms of SEO. Make sure, then, that the text is relevant to the image.

1. Add the caption

Why are captions important from an SEO perspective? Because people use them while reading the article. In fact, we tend to look at headlines, images and captions first while scrolling through a web page with our eyes.

In 1997, Jakob Nielsen wrote:

“Elements that improve scanning include headings, large fonts, bold text, highlighted text, bulleted lists, graphics, captions, topic sentences, and summaries.”

Jakob Nielsen

In 2012, KissMetrics went even further, stating that:

“Captions under images are read on average 300% more than the body of the copy itself, so not using them or not using them correctly means missing the opportunity to engage a huge number of potential readers.”


Think of the visitor first and don’t add a caption just for SEO purposes.

2. Add alternative text

The alternative text (or alt tag) is added to the image, because, in case the photo cannot be shown, there will be a descriptive text that the visitor can read. For example, in the case where the reader uses a screen reader due to a visual impairment.

Be sure to add the alternate text to each image and make sure it includes the key phrase.

Add structured data and XML sitemap

Yoast SEO plugin gives us the ability to add structured data. By including structured data, Google Images can show your photos as multimedia results. This offers visitors more relevant information about your page. Google Images supports structured data for products, videos, and recipes.

Also, again with Yoast SEO, you can enable sitemap for images to provide more information about the photos available on your pages. This way you help Google crawl and index your photos as well.

Use a CDN

A CDN (Content Delivery Network) is a set of servers that. helps minimize the delay in loading web page content.. In this way, users all over the world can view the same content without having slow loading times.

Image CDNs are used to optimize your photos and deliver them to your visitor as quickly as possible.. CDNs can have various settings like, for example, converting all PNG images to WebP format. This way you will upload photos faster and offer the best image quality.

In addition to contributing to SEO and user experience, images can also play an important role in conversion. So don’t underestimate the importance of image SEO optimization.

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