Image SEO: Tried and Tested Tips for 2021

Written by: Akanshha Agrawal on

Image SEO is truly the name of the game in 2021. More people than ever are searching for images. On top of this, more and more content is being published on the internet. This requires innovative and engaging content for increasing user retention.

The best way to do this is to optimize your image. Don’t worry; it’s not difficult, and you will easily master it with a little bit of practice.

In this article, we provide an in-depth review of SEO image optimization. This will help your images rank higher in image search and increase the value of your content. After reading this article, you will be able to:

  • Select the right kind of image for your content.
  • Optimise images for the website to improve search engine ranking.

Table of Contents

Why Do You Need to Add Images?

Nearly 20% of all searches on the internet take place on Google Images. This means that by failing to add SEO pictures, you are directly losing out on 20% of the audience.

Apart from this, images also enhance the content you post on your website. Remember, the primary idea is the same. You want to create value for your audience. Adding audio visual content really helps with this and brings in a broader audience base.

Image SEO Part I: Finding the Image

Finding the right image for your content is the first part of the Image SEO battle. The reader will only see this and not the backend optimization. You want to make sure that the image catches the eye of the reader.

Use Original Image

Original images are those you or your team have specifically taken to share on your website. These kinds of images share the meaning of the content and engage with the readers. These are great for on-page image SEO.

Customized images are also a great way of developing a theme for your website. This will help readers connect with the content.

It’s always a great idea to mix images with text. For example, if the article is on “How to Train Your Cat,” you can add a photograph of your own cat with the text on the side.

Avoid Stock Images

Stock images are copyright free images that can be used for commercial purposes. There are many websites such as Pixabay and Unsplash that provide free stock images.

These pictures are intended to be generic enough to be used on a wide range of topics. They do not provide any specific insight into your content. You should avoid using stock images whenever possible.

As discussed above, the original customized images connect with the readers. Stock images cannot do this. However, stock images are completely useless either.

Think of it like this – adding stock images is better for image SEO than not adding any image, to use it as a last resort.

Use Alternatives to Images

Image alternatives such as graphs or illustrations are a great way to add value to your blog and improve image SEO score. We generally prefer this to photographs as it can be customized more than photographs.

Another advantage of using image alternatives is that you can create it yourself. You don’t need access to any fancy software. Simply head on to Canva, and you can design something within five minutes using their built-in templates. Here are some examples:

  • Small summary at the end of each section.
  • Cover image with a combination of vector illustration and text.
  • Poster with pros and cons of a particular strategy.

Image Size and Quality

Checking size and quality is a must for image SEO. The size of the image should be large enough so that all the relevant details are seen. At the same time, the size should not reduce the page speed.

The size of the file depends on what you want to convey. For example, if you have a photo-realistic drawing, you want the file size to be big. On the other hand, if it’s a stock image of a computer, you can get away with a smaller size.

Select Image Format

The image format is an important factor of image SEO.

Here are a few things that you should keep in mind for different formats:

  • JPEG files are generally smaller in size, but you might lose a bit on quality.
  • PNG files preserve the quality but are bigger in size. PNG files also supports background transparency.
  • WebP files preserve high quality with a smaller file size. However, this format is only supported by a few browsers such as Google Chrome, Microsoft Edge, Firefox, etc.
  • SVG files are typically used for logos and icons. You can easily resize these files without losing on quality.

You need to be careful about the use of different formats. Make sure the format supports the goal behind selecting the image.

Image SEO Part II: Optimising the Image

Now that you have selected the image, it is time to optimize it. This is the key for increasing image SEO score. Search engines use this to rank your image in search engine results. You should have selected your target keyword before you start optimizing the image.

Avoid Keyword Stuffing

The key point of image SEO optimization is that everything should look natural. Google is smart enough to detect keyword stuffing, and your rank will be impacted because of this.

The good news is that it is actually quite easy to use keywords in a natural way. This conveys to Google that the image is actually about that keyword. This will apply to every single section below.

File Name

The common strategy is to give a random name to your image — something like image123.jpeg or IMG01.png. Don’t ever do this! Google determines the nature of the image by looking at a lot of factors, one of those being the file name.

Due to this, the file name is critical for image SEO. Ideally, the file name of the image should include your target keyword. You can just write your target keyword as well.

Keep in mind that this should still look natural so avoid keyword stuffing. Look at these examples:

  • Good: cat-sitting
  • Bad: cat-kitten-kitten-training-sitting

Compress Image

On average, images contain 21% of the website weight. This means that reducing image size will massively improve page speed.

Compressing your images is a great way of preserving the quality while reducing the file size. This really is too good to be true, and you simply cannot miss out on this.

You can use image SEO tools such as TinyPNG or Photoshop to compress images. For WordPress image SEO, you can also use WPSmush.

Add Alternate Text

The alt text goes a long way in making the internet more accessible for visually impaired people. If someone cannot see the image, their reading software will read the alternate text to convey the meaning of the image.

It’s also great for image SEO. In case the image fails to load, the alternate text will be displayed in its place. Since it conveys the meaning of the image, it is also used by search engines to rank the image search engine results.

Look at the following example:

  • Good: cat eating her food
  • Bad: cat kitten kitty food bowl

Add Title Text

The title text is an HTML tag. You should use this to optimize your images. Think of this as similar to the file name of your image. The title text will be displayed when the user hovers over the image.

The title text is not as important as the alt text for image SEO. However, it is still helpful and very easy to add. The best thing is to simply add the target keyword or the title of your blog.

For example, if your keyword is “cat sitting”, the title text could just be “cat sitting”. If you believe the picture is more descriptive, you can add a longer title text.

Add Image Description

The image description is longer than the alt text. Due to this, it allows you to share more information about the image. The idea is to be descriptive but concise.

A great model to keep in mind is to divide the description into object, action, and context. This lets you keep the description simple while conveying the point. This is also amazing for image SEO.

Look at the following example:

Image of a cat being trained.Cat is trained by a professional at her home.
Image of a cat eating food.Cat is eating from her bowl.

Add Image Sitemap

Google uses images to better understand the nature of the content. You can help with this by adding image sitemaps.

Image sitemap is the structure of your website. Search engine bots use the sitemaps to crawl and index your website. This helps in ranking the website for the relevant search query.

You need to submit the sitemap to Google Search Console.

Use CDNs

CDN refers to the content delivery network. These work to cache the files on a particular website in multiple locations. This means that the browser does not have to request the website server for the file each time.

Instead, the file is cached at a server that the user can easily access. Once the files are cached, they can be retrieved a lot faster. This significantly reduces the load speed.

Browser Caching

Browser caching is another great way to improve image SEO score.

Browser caching is when your browser downloads the contents of a website. This is used for faster load time when you visit the website subsequenlty. This is because the browser no longer needs to request the file from the website server. Instead, it can quickly be loaded from the browser’s cache.

Use Responsive Images

Different screens have different resolutions. This means that a 720 – 720 px picture will not look the same across all screens.

For example, if the reader is accessing content through a phone will a small screen, there is no need to show a high-resolution image. More importantly, there is no point in increasing load speed by adding a high-quality image.

The problem is you can’t tell the needs of each user while uploading the content. Responsive images solve this issue. You need to the srcset HTML code for this.

This allows the browser to load different size images based on the device used by the user. This massively increases efficiency and reduces load time. It’s great for image SEO.

Check Image Placement

You will be surprised to find out how important image placement is for image SEO. Most websites simply paste an image within their article to improve the SEO score. However, this does not improve the user experience.

You should add the image next to the text related to it. This will provide a context for the image and help the readers in better understanding your point.

Optimise for SafeSearch

Google uses SafeSearch to determine which users wish to see explicit images and videos. It’s really important that you let Google know about the nature of the content.

Google’s algorithm does use a wide range of factors to determine if the image is adult content or not. However, it’s not perfect, and you should take some steps to help in the process. One of the things you can do is group all the sexually explicit images on your website. This will easily create a distinction between the content on your website.

Another good practice is to add metadata to explicit content. The metadata is one of the strongest indications of the nature of the content. You can self-mark explicit content so that it is only shown to the appropriate audience.

This will also help attract the right kind of user base to your profile and improve satisfaction when they read the content. Remember, the goal is always to attract a quality audience that will stay loyal to your brand and achieve consistent growth.


Image SEO has a lot of power to increase the audience on your blog. You should use it along with the larger on-page SEO strategy.

It is quite easy but does involve many steps. It’s best to keep a checklist and run through it each time you share new content.

Here’s a quick overview of everything we discussed for perfecting image SEO:

  • Add original images and illutrations instead of stock photos.
  • Select the right size and format depending on the nature of the image.
  • Choose the right file name.
  • Add an alt text describing the image.
  • Use the target keyword in alt text, image title and image description.
  • Use browser caching and CDN to reduce load time.
  • Opt for responsive images which adjust to the reader’s device.
  • Use images in the sitemap.

There you go – the complete image SEO guide! We hope this helps in optimizing your images.

Feel free to leave comments if you have any doubts, and we will answer them ASAP!


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