Image SEO: Alt tags, alt text, optimization – SEO Tips and Tricks

Image SEO alt tags

What is the first thing that comes to your mind when we talk about image SEO? Maybe Alt tags? Certainly, for me it is. But image SEO is much much more.

So what exactly is image SEO?

Image SEO is the process of enhancing web pages so they rank better in search engine result pages for queries that involve presenting images and other multimedia content. Image SEO is also known as Search Engine Optimization for Images or SEOi. The process involves optimizing each image and thumbnail, producing alternative text (or alt text) that search engines can read and index to improve a web page’s ranking for specific queries. It also requires the use of descriptive image titles in addition to alt text.

Why is image SEO important?

In this image I am describing the alt text of this image that I am showing right now. It is ALT Text inception :O
Last 12 months, search type: Images

The importance of images is not only limited to its search engine ranking and SEOi. It also gives you more control over the user’s experience and usability of your website. The user will be able to get a good idea of what your business is all about, just by looking at the images you have uploaded. For instance, if you are an interior designing company, a user can get a good idea of the kind of designs and styles you offer on your website, by just looking at your images (provided that they are attractive). Some businesses are solely dependant on their images – photography studios, photographers, clothes, paintings and etc.

Now that you got a fair idea about what is image SEO and why it is important, let’s get back to our topic.

What are Alt tags and Alt text?

Image SEO starts with Alt tags. Alt tags can be used to describe the image and its context. Those are tags that should be placed inside the  tag. They help search engines understand what an image is about. It helps search engines index images for better search results and gives you more control over how your images are displayed in Search Engine Result Pages (SERPs).

How to optimize Alt text?

It is not necessary that you write an Alt tag or Alt text every time you upload an image, but you should always use it when you need to describe the image or want your images to display correctly in Google’s results. You should only use alt tags/alt text when you have something to say about the images, don’t just use it for the sake of using it.

Now the question remains, what exactly should I write inside the alt tags?

The Alt tag text should be relevant and descriptive as much as possible. It should be 100% unique. Search engines will not index the images with duplicate alt text. That lowers their quality.

There are two possible ways you can write your alt texts. The right way and the bad way:

The right way: You have enough time – Describe everything you see in the image for each image on your page in form of alt text.

The bad way: You don’t have enough time and you have to optimize as fast as possible – Grab your page’s title and add numbers after it. (Example: “Image SEO and Alt tags 1”, “Image SEO and Alt tags 2”).

The second method is 90% of what people do and that’s why they don’t get results.

How images impact page speed score?

Image SEO also helps you with your page speed score. Images consume most of the bandwidth which is why slow website speeds irritate users. A slow website can cost you potential customers. Google uses page speed as a ranking factor in its search results. If your website loads fast, it is more likely to appear at the top of the search results for relevant keywords. In one experiment, I found that where a 1-second delay in page speed resulted in a 25% decrease in traffic from Google.

Google also takes into account how your pages render on mobile devices. Therefore, if you are using slow-loading images on your website, you might get penalized for it (or not rank well in the SERP).

Is the file name important for image SEO?

The file name of an image is the first piece of information that search engines see, so you should always be careful about it.

If you are out of ideas on how to name your file – use your page title as your file name. It will help you with Image SEO and alt tags for images, as well as help with page speed score. Keep the filename short for search engine convenience and user experience, but descriptive for humans.

The best way to go is to name your file with the keyword that you wish it to be associate with. Why? Because the file name is responsible for the URL of your image when it is uploaded on your website.

Good file name = good image URL.

Structured data for images

Evaluating an image should be a breeze for the search engines with the help of Structured Data. It is basically a markup pattern, that gives search engines useful information about your images. It helps users to easily find and explore image content on web pages.

Structured data helps the image show up and rank in Google’s image search results. Not only that, but it also allows you to place image thumbnails in your SERP rich snippets and take your website pages to the next level.

How to add structured data to your images?

First of all, you should know that there are two ways to add structured data to your images.

  1. Use Microdata (HTML tag) to mark your images and make them rich snippets (HTML optimized for SEO).
  2. Use the JSON-LD structured data format to mark your images on your blog posts.

JSON-LD is the preferred way of adding structured data because it works with Google’s Rich Snippets. There are two ways to add JSON-LD to your site: manually or by using a plugin.

Manually – Use Google Webmaster’s Structured Data Markup Helper. It is a free tool provided by Google that helps you with adding the right tags to your images and HTML pages. It is very user-friendly and it takes only a few minutes to learn how it works. Automatically – You can simply use one of the plugins listed below, which will automatically add structured data markup in your existing posts.

Using a plugin to add structured data automatically would generally be the simplest and most efficient way to go. If you use WordPress, of course. However, WordPress users prefer not to install plugins because they are afraid of affecting their website performance. In cases like this, manual adjustment is your only option.

I recommend that you use the plugin called JSON-LD Structured Data for WordPress. This plugin is easy to use, completely free, works for both images and posts and supports all kinds of media types.

Additional tips for image SEO

Tip #1: File types

You should use formats that are best suited for image SEO. For example, JPEG files have a smaller file size compared to PNG and GIF files, but they don’t have built-in text descriptions that search engines can recognize. However, PNG files have a larger file size than JPEGs but they include text descriptions that show up in your search engine’s results page (SERP) in the form of titles and alt tags.

Tip #2: Image size

This is another important thing to consider when uploading images. Images with high resolution and large file sizes take a longer time to load. Depending on your website’s setup you can make the image size smaller by resizing or using lighter backgrounds (if applicable). The general rule of thumb is that you should aim for an image size as close to the original file size as possible without compromising any quality or details.

Tip #3: Image location

Where you place images on your page matters. The image SEO depends on where you place the images. The best practice is to keep the images in alt tags and title text as close to the content as possible. It also matters if there are other relevant images around but that isn’t necessarily a bad thing. If you have multiple relevant images, it helps Google understand what your page is about and rank it higher for relevant keywords.

Bonus Tip: Image Sitemap

An image sitemap helps Search Engines better understand what images are on your website. The sitemap also helps you easily manage your image SEO. You can use the sitemap to upload all of your relevant images from one central location instead of uploading them on separate pages.

Consistency is key when it comes to search engine optimization, and that’s why you should be implementing image SEO as part of your website’s overall SEO strategy. It might not seem like much, but it does go a long way in helping improve the quality of your site. You might be surprised how many people will visit your website from Google Images.


Image SEO is one of the most underrated traffic sources and aspects of search engine optimization. A lot of users browse Google images before they decide to take action. If you have good image SEO then you can get potential customers from not so competitive part of Google. Be proactive and shine above your competitors with amazing images!

I hope that this article was useful for you and you found some hidden gems in it.

See you in the next one!

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