What Is The Purpose Of Image Optimization For SEO?
Search engines don’t comprehend images the same way a person does. Search engines need additional text identifiers to give as close to a full understanding of what an image is and what it’s trying to show. Additionally, there are a few other elements that need to be taken into consideration to ensure you’re using images to their highest potential for SEO gains.
Before we go into how to optimize the images on your site, let’s go over a few basics. There are three main elements of your image that need to be taken into account when looking to optimize your image:
Image Source (in HTML: “src”) – This is the name of the image file displayed on your page.
Image Alt Tag (in HTML: “alt”) – The attribute is used to describe your image in a textual format. This allows search engines to get additional understanding of your image since these search engines can only “see” the images, not necessarily comprehend the image.
Image Title (in HTML: “title”) – This is the title of your image.
Include a keyword rich URL name to provide a detailed description of your image right off the bat. For example, “chicago-skyline.jpg” is more informative than using “image1.jpg”.
Image Alt Text: Include keyword rich image alt text as a way to describe what the image is about to the search engine. This element can help support keyword targeting, and when alt text is crawled it is taken into consideration in Google’s core keyword ranking algorithm.
Avoid embedding valuable text in your images: When creating images, it’s important to avoid included text in the image itself. When styling your website, ensure the text is a separate element on top of the image and is able to be crawled.
Image Size & PageSpeed Concerns
A common PageSpeed issue on websites is that image files are too large and take a long time for the device to load them. To alleviate this issue, you can use lossy or lossless compression to reduce the file size. Lossy compression will somewhat degrade the quality of the image but reduce the file size the most, whereas lossless doesn’t degrade image quality at all but the file size won’t be reduced as much.
Automate image compression. Use tools such as Compressor.io and WP-Smush (for Wordpress sites only) to help automate image compression tasks.
Use Image XML sitemaps to increase the chance of your images being indexed by search engines. Tags such as <image:caption> and <image:title> can be used within these sitemaps to provide additional information about your images.
Rich Card Image Requirements
Rich Cards are a type of search result that uses schema markup to display select mobile pages as a card in the SERPs.
In order to have an image properly render for a rich card, images need to be a minimum of 185px by 185px size – anything larger must retain the 1:1 aspect ratio.
Creating A Positive User Experience With Images
Having the best quality photos possible on your site is always recommended. Images that display well on both the landing page and thumbnails is key to enticing users to potentially click through to your site.
Just like when creating and placing content on your site, images that live closer to being above the fold will put your image in a better position to get viewed by users and picked up by search engines.
Resize images in order to have the specified size of the image fit the size of the onsite display. Images that are larger than the size of the onsite destination can lead to page speed issues & potential responsive design issues.
Specifying image dimensions can help browsers render a page in a more efficient manner by saving load-time. The faster a pages loads, the better user experience your site will offer.