May 23

Comprehensive Guide To Image Optimisation For SEO

The world relies on visuals for everything now. The value of image optimisation can’t be stressed enough. If your images are not high resolution and easy to load, then you could have problems with page speed. However, there are also SEO tags that need to be added to images in order to describe them for search engine crawlers. To improve your Search Engine Optimisation you need to improve your images. Google and other companies around the world are certainly bringing you a lot of tools to improve your images. With the advancement of HTTP2 and wide availability of CDN’s, ensuring that media content loads faster is absolutely mandatory for webmasters.

There’s probably an image on every page of your website. If you are not optimising each of these images, you are wasting a valuable piece of SEO investment. With proper image optimisation, your visitors will have a better user experience, faster page speed, and higher SEO rankings. Small businesses can compete on a larger scale with competitors just be improving their use of images and SEO.

Visual search engine technology has improved in the past few years. Search engine crawlers have come a long way, and while images can be identified, crawlers still have a hard time understanding what an image is without a keyword in an alt tag. The text associated with the image helps the crawler relate it to the rest of the content of your website. There are some factors that matter more with image SEO. Especially with the advance of AI and Google rankbrain, it is imperative that your images are not only optimised but are also meaningful. Here is a deeper look at what you can do with your site’s images.

Some major points to consider for image optimisation:

  • Name your images in plain language
  • Use keywords in description and titles
  • Optimise alt attributes to have an impact, don’t keyword stuff
  • Choose image dimensions wisely to fit the element on your page
  • Reduce the size of all images to make your page load faster
  • Pick the right file types like JPEG for better quality
  • Improve JPEG quality using web and devices format
  • Optimize your thumbnail images for social media sites using OG
  • Use image sitemaps to better inform search engine crawlers
  • Don’t place multiple images on a page or blog post unless each provides impact
  • Test your image optimization through sites like Screaming Frog and Xenu

Stock Images Don’t Work with SEO

If you want photos to help your site rank, then you should always use original photography. Stock photos can be purchased by anyone and placed on any website. If you use stock image content, then you are trying to rank your images against thousands of websites that already use the same images.

What is this image for ?

What is this image for?

In addition, visitors can tell the difference between real and stock photos. Eye movement studies show that users typically skip over unoriginal content.

Create Original Content

With original photos, you wield a higher power over your content. It also creates a more visceral experience for the user that creates better memories and relationships with your content. If you want to create an experience that resonates with visitors, then original designs, photography, infographics, icons, and visualization graphics are always helpful.

Image needs to be relevant to content

Have you ever browsed your website as an objective user? Have you looked at your site as a person who has never met your brand before? If so, you may notice that certain images may be too obvious or do not have the same impact as others. The images on your site should be there for a reason.

Nihilism XKCD

Nihilism XKCD

Images can direct the eye, convey messages, and break up the text. You can use images to tell a story and add meaning to your landing pages, articles, and blogs.

Avoid Copyright Problems

Found an image on the net that perfectly describes what you want your page to say?

Not so fast!

These images are probably protected under copyright, which could lead to fines and penalties if you use them on your website. Most of the time, stock photo companies will file a cease and desist with a request to pay a small fee for using the photograph. However, you should always make sure that there is no image conflict. Shutterstock, Getty, iStockPhoto, and other image sites own the image and will provide you with a license to use the site, according to their rules, for a certain price.

copyright problems

Google Images licencing filter

You can filter image results in Google for “available to reuse,” but this still isn’t as good of an option as taking your own photos if possible.

Optimise with right Image File Types

Most images for your website will be JPEG or JPG file types. However, you may have SVG, PNG, GIF, or BMP. However, JPEG retains the most value when resized or compressed. You can use JPEGs for high-resolution image. It’s also the most recognized image file type across all devices and browsers.

JPEGs can be resized down to small file sizes pretty easily. The image quality can go down with lossy data compression, however. In addition, if you want any transparency, you will need to use GIF and PNG formats.

PNG images are made using Photoshop and can handle transparency. They are used mostly for logos and high-resolution graphic designs. There are a couple of different image file types including PNG-8 and PNG-24. These display in a higher resolution and appear crisper. However, they are not the best for page speed optimization as it takes a long time to load.

GIFs have the same problem with page load and page speed. While you can get a small image size from a compressed GIF, the details and quality tend to lessen dramatically each time that the GIF is compressed or changed.

Optimize File Size Without Diminishing Quality

Images are the number one problem for fast page speed loading. The file size is one of the most important parts to page load optimization. If your site’s speed is too slow and it takes more than a couple seconds to load a page, then you could be losing valuable traffic from visitors who bounce off.

The size of your image should not be any bigger than the dimensions you actually need. This means that if you have a blog post that is 600 max width, then you should have an image that is the exact size. When you use JavaScript or other code to resize and compress images on your site, you add more page loading problems to your site.

You can use features like “Save for Web” in Adobe Photoshop to optimize an image’s file size. You can use Photoshop presets to help with size and image quality.

Your image file size should be between 1.38MB and 86k. There are also a few tools that you can use online to compress your image files. You should always look to compress images without sacrificing crispness.

If you notice that an image becomes pixelated or distorted after you compress the size, then you should revert the image back to the original file and try to compress with another tool. You never want to sacrifice the sharpness of your image.

Descriptive Captions on Your Images
Adding captions to your images is important for SEO and user experience. You should be able to describe an image on your site. The caption is the text that appears in an outlined box typically below the image. You can explain who is in the picture or what is being shown, and you can choose words that also include keywords.

Captions also help users because not all photos make sense right away. You may want to add more context and other keywords for search engines. Paynter Research recently revealed that captions see 16% more in readers than an image without one. Great images should accompany great metadata including a great meta description and an absolutely descriptive H1 tag.

Not all images require captions, and there will likely be some images that look better without one in your web design. You should simply make sure that the caption is text-based and not included in the image, as this won’t help you reach search engines.

Name Images for SEO

Descriptive, keyword-filled file names are important to helping search engine crawlers understand what’s in the photo. If the crawler can understand the subject matter of the image, it can quickly determine how relevant your content is to certain queries being searched by users.

The file name usually looks like “IMG_722011.JPEG,” so you should always change your image names to reflect what they are about. For example, an image about a wedding in Melbourne on a beach might look like “Melbourne_Beach_Wedding_2018” when it is renamed. This helps provide more SEO value to your images inherently.

You want to avoid using generic names whenever possible as this doesn’t help you rank against competitors who may be using the same image types. For example, you wouldn’t want to use “wedding-1.jpg” or “wedding-2018” as these are generic or not evergreen enough. You should use short keyword descriptions that are easily recognized by crawlers and can be found in queries that you want to rank for.

Add Alt Text to Images for SEO

In some cases, a browser can’t load the image on the page. Perhaps a user has turned off image loading to preserve data or your server isn’t loading the page fast enough. In any case, the alt text will display instead of the image. Alt image attributes are important to add to every image for this reason. You want to make sure that your alt text has the right keywords as well.

On-page SEO strategies cannot work without alt text added to images. Alt tags also help with ranking by tagging your content with certain keywords that you want to rank for. Google has stated previously that image alt tags are key to helping search engines learn more about your content. If you have a lot of images on your site, then each one should have unique alt text.

In addition, some say that alt text is required, particularly for those who abide by the American Disabilities Act. This means that if someone is unable to view the image, then they must have the alt text appear instead.

So how do you add alt text? It depends on how your site is built. In some cases, you may be using WordPress, which allows you to edit the media file and add alt text to any image. If you want to add it manually, then you can do so as follows:

This shows you the name and alt text. If you want to amp up your SEO signals, then you can also use the alt text as the anchor text of internal links for the image.

Create Image Sitemaps

All sites should have a comprehensive image sitemap that houses all of the images in one place. This helps search engines discover images easily on your site and increase the chances that your images will be displayed in search results along with the rest of your content.

Image sitemap

Image sitemap

You can create an image-sitemap.xml that will show Google and other search engines how images have been uploaded through JavaScript. You can call out images with this XML spreadsheet that you want to be crawled as well. You can create an XML sitemap just for images and add all of the information, including alt tags, to the document as well.

WordPress and Shopify plugins like Google XML Sitemap for Images make it easy to create and publish these types of sitemaps.

Ensure Open Graph & Twitter Cards Data is completed

If you know that your content deserves to be shared, then you should make it presentable to social media websites when linked by your users. This means adding Open Graph (OG) and Twitter Cards to your content so that the right images and headlines display when your site’s pages are linked.

In some cases, you can use a WordPress plugin like Yoast for SEO to add images to each post. However, you can also manually set up Open Graph within the code of your site. For OG tags, you should set the image and metadata up to show the right messaging and visuals. You can add these tags in the head section of your page. Here’s an example:

<meta property=”og:image” content=”https://website.com/SEO-image.jpg”>

Twitter Cards are set up similarly and have the same role as other sites when shared on Twitter, driving up clicks and engagement. Setting up Twitter cards gives you a bit more control over the content that displays when something is linked on Twitter.

Tools for Image SEO

There are a few tools that you can use to audit your site. These tools like Screaming Frog, SEMRush, RavenTools, and Xenu will crawl your site and generate a report on what you need to do to improve your SEO. Most often, the lack of image tags and image file size are the main problems on the report. The audits provide you with a list of pages that are not optimized, and in some cases, like SEMRush, you will also get instructions or ideas on how to improve the site further.

Keyword tools within Google and SEMRush are also important for SEO copywriting. Google’s keyword planner tool is a great option to learn low, medium, and high keyword volume groups. You may not be able to compete with competitors in certain keyword categories, but you can find some keywords in low-to-medium volume that are worthwhile.

If you run PPC ads on AdWords, you probably have a history of search terms that you can check out as well. The search terms feature can be accessed by clicking on any of your ad groups in AdWords, then clicking on “Search Terms.” It will display the most common queries that pulled up your ads in the past. This gives you insight into long-tail keywords that you may want to use on image captions, alt text, FAQs pages, and general SEO keyword optimization. You can then utilize PPC to improve your SEO.

SEMRush provides an in-depth keyword tool as well that you can use to track competitor keywords and your own, providing you with new ideas on how to rank up in certain keyword groups. You can also measure your performance over time, see your rankings go up and down, and check against competitors in the same market.

Image Optimization for Ecommerce SEO

If you are trying to rank up with your online store, you may find that it requires a lot of social media marketing. However, you should make a point to elevate your SEO on product images, product descriptions, FAQs on product pages, and so forth.

Many online retailers also create hundreds of SEO pages that categorize and group products, such as “Fashionable Flats for Women 2018.” If you own an online shop that specializes in women’s shoes, this SEO page and the images linked on that page are very important to your ranking. Pages like this can grow your SEO over time and get shares on social media.

Optimize with a CDN

A content delivery network (CDN) has become standard for storing images on your website so that the page loads faster and can be accessed from any location. As there are so many people with mobile devices today, you never know how someone is trying to access your site. With a slow loading site that doesn’t have a CDN, users may not be able to see images and bounce off your site.

There are a number of affordable options, and there are some hosting sites that include a CDN service. You should consider using a CDN for the following reasons:

The worst thing that could happen for your site is that it fails due to bandwidth problems or images not loading on the page. Using a CDN can protect your site from these instances, effectively giving your site a suit of armour.

Make Your Images UNIQUE

Even though it’s best to create your own content, it’s not always possible to do so right away or you may not have the right camera equipment. In that case, you can always change the stock image by adding text, filters, icons, and different layers. You can use tools like Photoshop, Canva, or Picasa to change your images if you must use stock images.

One way to change stock images is to add quotes from the article as a text overlay. You can also combine images through blending techniques. You may want to use a designer to help you craft images if you want each image to have certain colours or match your brand identity.

Image Optimisation checklist for SEO

The following tips should give you a starting point for improving your images and SEO strategy. As you start to optimize your site, you should use tools like Google’s PageSpeed Insights or Pingdom to let you know if your image sizes are contributing to any slowdowns on your website.

With proper image optimization, users and crawlers alike will be able to understand your images better, and it will improve your SEO rankings over time. The most important things to make sure with images and alt text is relevance. Your images and keywords should always relate to the subject matter of your page and overall website.

Here are some other key takeaways for image optimization in SEO:

  • Keep image file size below 2000 pixels
  • JPEGs offer the best quality and performance for images
  • Do not use PNGs or GIFs for larger images
  • Make stock images more unique with services like Canva or Photoshop
  • Describe the photo with proper keywords and avoid keyword stuffing
  • Images should always relate back to the content of the page
  • Create an image sitemap for search engine crawlers
  • Use OG and Twitter Cards to improve how content displays on social media
  • CDNs help your site load faster for mobile users accessing from any location

Above all, treat your SEO like a growing houseplant for your website. After you optimize, you should continue to tweak content and update older site pages so that you are constantly feeding your users great content that they want to share. We at Weboptimizers treat image optimisation as a key requirement for better SEO results.

About The Author

Ajay Chavda is the co-founder of Weboptimizers, an SEO agency in Melbourne and has been involved with SEO for over 15 years. Between the digital properties and security forums he has managed, his articles have been read by approximately 50 million unique visitors.

1 Comment

  1. kumar
    October 10, 2018 at 5:04 pm · Reply

    hi Ajay,
    thank you for the informative article.
    you covered a lot of useful information that a lot of webmasters can learn from.
    i just want to add i found a free online sitemap generator for images.
    this can save some time and effort for some people: image-sitemap.net

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