Optimising Images for SEO in WordPress
Images have a number of effects on a webpage. Images can be used to either make the page more visually appealing or convey information. On a well-designed page they will do both. A well-optimised image will also contribute to the pages SEO. Images can have either a positive or a negative effect on your SEO. While this blog post is specifically about how to optimising images for SEO in WordPress the principals are the same for other CMS.
Optimising Images for SEO in WordPress
Potential Negative SEO effects
There are two primary ways in which an image may have a negative effect on your page. Firstly the size of the image can have a detrimental effect on page load speeds. Google prefer websites that have quicker load times, so do users. One of the many factors that effect page load speed is the size of the images on the page. Therefore it is good practice to compress any images that you are adding to the site. A handy tool for this is tinypng. You can simply drag your image into the box and it will compress it for you. Then you can save it to your downloads before renaming it and uploading it to your website.
The second way that images can negatively affect your SEO is by giving mixed messages in regards to the content of your page. Imagine your page is about water buffalo and you have a photo you would like to add to the page. The photo shows a lion ready to attack a water buffalo. Your image could be called lion-pouncing.jpg. Your image alt text could be something like “Lion preparing to pounce”. This confuses Google. Your page title is “Water buffalo”, your H1 heading is “Water Buffalo” and you have the subheadings “Water Buffalo Habitat” and “Natural Predators of Water Buffalo”. Your image appears to google to be about Lions, therefore, your page will be deemed to be of slightly less relevance to a search for “Water Buffalo” than a similar page where the same image has been named “water-buffalo-predators.jpg with alt image text that reads “water buffalo about to be attacked by Lion”
This is a particularly common issue on business websites where the same image may be used on multiple pages. When this is the case you should save the image to your desktop, rename the file, then upload it to the media library again as a second image named to fit the new pages SEO theme. Finally add a new alt image text that is in alignment with the second pages SEO theme. Do not simply grab the image from the image library and overtype the title and alt image text when adding the image to the second page.
Changing the title of the image in WordPress does not change the file name. This must be done by using “save as” then renaming the image outside of the website. Changing the alt image when adding an existing image to a new page will change it on both the new page and the old page. This can destroy yesterday’s SEO efforts. You must re-save and upload a second copy of the image with a new file name to be able to give it a new alt image text appropriate for the new page.
Positive SEO effects of well-optimised images.
What are the positive effects on your SEO of a well-optimised image? It does two things.
Firstly it makes the page more friendly to the visually impaired. Blind and visually impaired people browse the internet with special browsers that read the contents of the page to them. When these browsers get to an image they read the alt text to the user. This gives you some clue as to how best to use the image alt text block. I recently looked at a wedding photographers website that contained a page they were obviously trying to SEO for Hamilton Wedding Photography. They had put “Hamilton wedding photography” as the alt image text for all of the 32 images on the page. Can you imagine how unbearable that would be for a blind person whose browser would read the same alt for each image one after another 32 times?
You should write the alt image text with both your SEO target and a blind person in mind. If you have copied and pasted the same alt text to every image don’t expect to gain rank for it, you are more likely to be penalised. You should spend the time to write a proper description for each image. For example “blushing bride is kissed on the cheek while posing for a wedding photo in Hamilton gardens” you can use similar file names for example Rachel-Steve-Wedding-Photo-Hamilton-1.jpg and Rachel-Steve-Wedding-Photo-Hamilton-2.jpg etc.
Google want to make the world (and the internet in particular) a better place, they seem to genuinely boost the rank of websites that follow recommended best practice for the disabled.
The second way that a well-optimised image boosts the SEO of a page is as mentioned earlier, is by improving the page’s relevance to a given search term. Imagine two similar websites, each with the same number of links from similar sources. Both websites contain 500 words of well-written text on the same topic. One page has no images and the other has 3 well-optimised images. Google will rank the page with the images higher. Google always try to show pages that a user will find most useful. In many situations a page with images and text is usually more engaging, better at explaining and more entertaining than a page with no images.
Googles view of images
Well-optimised images will also appear in Google Image search results. Remember Google can see your image, but not quite as well as a person. Google rely on your assistance to tell them what the image is. The primary methods to tell Google what your image is about are the file name and the image alt text.
A visible caption is also mentioned in google’s webmaster guidelines, but as it is visible it can interfere with the design of your page so use your discretion. Remember there is no one single key to good SEO. There are thousands of factors that all make a small contribution to the total effort.
Google’s recommendation is to produce high-quality content and share it as widely as possible. As long as you follow best practice the rest will take care of itself. You can read google’s view on images here https://webmasters.googleblog.com/2012/04/1000-words-about-images.html
If you are unhappy with your current google ranking and would like help optimising your images for SEO please get in touch. We can help you improve.