An Essential Guide to Image Optimisation for SEO in 2019
Updated on: 9 May 2019
In the Search Engine Optimisation (SEO) process, images play a vital role as it accounts for a significant portion of search queries that are generated in search engines. Images are essential in supporting a page’s content while also enhancing the overall user experience, and is an important source of garnering web traffic.
In fact, prominent analytic platforms have shown that webpage traffic driven by image search have increased exponentially, enabling content visibility to be elevated. This has driven a wide range of companies from different industries to hire a top Digital Marketing Agency to support them on their quest to rise the ranks of SERP.
So how exactly do YOU go about doing it? Let’s take a look below.
SEO Image Naming and Description
A key SEO opportunity that you should take advantage of is naming and accurately describing all of your images. Using relevant keywords that closely corresponds to the description of image files enables a better ranking result. For example, images that are used for ranking should have keywords separated by hyphens, and avoid the use of stop words such as “in” or “with” as much as possible.
In addition, using alt and title descriptions is a complementary method of enabling images to earn a higher ranking in SERP, while simultaneously improving user experience and building the relevance of your page. The descriptions also serve to establish context for image links, improving the page’s relevance and value in the eyes of Google – which is always a good thing.
In the case of product and e-commerce image files, adding SKUs, model numbers, and ISBNs (International Standard Book Numbers) to the alt description improves the search experience by being more specific.
Coupled with on-page image captions and content-included keywords, the page’s ranking ability is improved as search engines are better able to read and interpret your website. If all this sounds like mumbo jumbo to you, consider engaging a Digital Marketing Agency offering SEO services to get the ball rolling.
File Size, Image Dimensions and Formats
The load time of a page can be affected if an image’s file size is not optimised. In general, using an image in JPEG format benefits SEO far better than other formats such as PNG, as they provide enhanced compression levels. For images using the GIF format, try using a smaller colour scale for faster page speeds.
For the actual image size, it’s recommended that they be below 100kb to prevent increased page loading times. If a larger image is needed, opt for progressive JPGs that loads progressively together with the page. In essence, first choose the ideal format for your page, then tune the image settings accordingly.
Image dimensions for SEO should fit within the largest screen resolutions to avoid it being scaled down by browsers. Ensure that the site’s CSS (Cascading Style Sheets) enables your image to respond to varying window sizes automatically too. Some common image compression tools such as GIMP, Smush, and MinifyWeb are extremely handy in adjusting the right image dimensions for your page.
Image Hosting and Caching
While images can largely impact a page’s loading time depending on its file size – this also multiplies the number of requests sent to a server that once again, leads to a slower page load.
Selecting the right hosting of images on a domain can be highly beneficial for SEO as it enables control to be established over the branding, the control of redirects, and cache control. HTTP/2, the major upgrade of HTTP, is highly preferred so that multiple server requests can be executed simultaneously.
Another image factor that affects a page’s loading speed is how the image is loaded. While the HTTP/2 network enables a noticeable improvement in loading multiple images at once, page speeds can still be slow if multiple images need to be used. If so, try the lazy loading method – which essentially loads your above-the-fold content first, moving on to load the remaining images only when needed.
Using structured data such as microformats and schema markups is another useful way of improving the indexing of your website – including images into your page’s structured data helps you create rich results, which have been shown to be successful in winning more clicks.
Essentially, ensure that you scale images to their optimum display size so that the page does not spend critical resources scaling down large images – focusing instead on serving a valuable webpage for users.