Image SEO checklist: image optimization to boost your website’s ranking

Every website needs visual elements. Image files therefore also play a central role in search engine optimization. But image SEO isn’t just about image optimization, it also includes on-picture, on-page, and off-page factors.

Image SEO is not only helpful for the ranking of your images.
Image: © Nmedia / Adobe Stock
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What is image SEO?

Whether online store, company advice blog, or corporate website: none of these formats can do without suitable visual elements such as images. They are an absolute must. Not only are they a direct ranking factor themselves, but they also have a massive indirect impact on your positioning in SERPs because they significantly contribute to the user experience of your website visitors. Consequently, images are instrumental in boosting your traffic and conversion rate.

Who would buy something in an online store if the items aren’t presented using appealing images? Who would really read through a whole blog of tips and tricks if it didn’t have images or graphics to visualize what the author is trying to communicate? Who would take your brand and company seriously if your online presence is a sheer jungle of text, made a little more exciting by nothing more than a team photo and corporate logo?

Images are an essential part of search engine optimization if you want to create a successful website. Image SEO as an on-page SEO discipline is about optimizing the visibility of your website using images and graphics.

When Googlebot parses a website, it also stores all the image information, which includes alt tags, image file name, and the like. This data, together with the relevance of the webpage the image is located on, but also the website as a whole, determine the image’s ranking in Google’s image search.

Why image SEO?

The main goal of image SEO is obvious: optimizing images to make them easier to find in image search results. However, image SEO isn’t just relevant for making your images show up at the top of search results, but also for increasing the organic visibility of your entire website. If you don’t pay due attention to image SEO, you are inadvertently damaging the ranking of your website. That is because Google uses the image information to not only display images in its image search results, but also to better understand and index the surrounding content on the website. Search engine optimization is therefore nothing without image SEO.

The two key advantages of image SEO are:

  • Website images are easier to find using search engines, thus drawing organic traffic to the website.
  • Image SEO strengthens the overall relevance of a web document (webpage) with regard to a specific topic and thereby increases organic visibility.

Traffic magnet and conversion driver: top ranking in image searches thanks to image SEO

Visual search is becoming increasingly relevant. Google’s image search can be a real traffic magnet for your website if you offer valuable, unique, and keyword-optimized (particularly in terms of your main keyword) visual content. Image results are part of Google’s universal search and are displayed in a prominent spot in the regular web search when certain search queries are entered.

Consequently, meticulous image SEO offers you a direct advantage, since your visual content will be easier to find and displayed more frequently. And we’re not just talking about product images to satisfy a transactional search intent – visually appealing statistics in the form of charts or elaborate infographics can also give users enormous added value and encourage them to visit your website. This guide by visme shows you 9 steps you need to follow to make an infographic that stands out. By the way, a large proportion of image search results come from Pinterest, so it also pays off to turn your images into Pinterest boards and stories.

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What are ranking factors in image SEO?

Search engine optimization doesn’t mean image editing or packing your website with glossy, high-resolution digital shots that have maximum eye appeal. Instead, it’s about specifically optimizing the properties of an image and the corresponding webpage.

Artificial intelligence and machine learning already allow Google to identify and label the objects, texts, people, and actions depicted in images (using the Vision API tool, for example). As a result, you can influence the main terms used by the search engine to label the image and only choose ones that match your intent.

Generally speaking though, Google and other image search engines are still text-based search engines that extract the information they need to label and display images from the data stored in the HTML code. Therefore, it is mainly up to you to determine what data you make available here for them to categorize your image and rank its relevance to certain search terms. However, text contained in an image or graphic will also be analyzed and used for indexing.

Of course, Google doesn’t fully disclose its ranking factors for images. As is the case with other SEO disciplines, many criteria remain a secret. That said, the most relevant ranking factors in image SEO can be split into the following three categories according to content and technical aspects:

#1 On-picture factors

  • Image size: the size of the image or image file
  • Image format
  • Image naming: filename and URL of the image (image URL)
  • File format

#2 On-page factors

  • Integration of keywords, particularly the main keyword
  • Context of the image and surrounding text
  • Alt attribute (alt text, alt tag): alternative description of the image content in the form of text stored in the HTML code
  • Image title tag: additional image information that appears on mouseover and improves usability
  • Content quality

#3 Off-page factors

  • Internal link structure
  • External link profile (backlink profile)
  • Originality or multiple use of the image and related content (unique content)

In our free image SEO checklist, we elaborate on each of these factors and walk you through them all step by step.

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Image SEO: optimization means finding a balance

There is no one right way when it comes to search engine optimization for images; it’s often about compromise. For example, images should generally be of a high enough resolution for users to still be able to make out details when they zoom in. Low resolutions appear unprofessional and hardly reputable, thereby leading to a poor user experience – which is disastrous, and not just for an online store.

However, a large format and high resolution increase the file size. That in turn impacts the load time of the webpage, which is an important ranking criterion. With that in mind, you need to find a happy medium and incorporate high-resolution images while making sure their file size is kept to a minimum. Choosing the right file format plays a decisive role here if you want to offer good resolution and impressive page speed without losing any important image information. Our free checklist tells you exactly how to achieve this.

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