How to optimise your images for SEO
There are many areas of a website that can be optimised to improve your SEO and enhance your search results.
Many websites only account for the text you can read on the page as a visitor, but to make the most of your website in search results, making sure you address as many areas as you can is the key to improving your ranking and quite possibly, your sales on e-commerce websites.
- Creating your image:
Whether you have your own photographs, or source your images from online stock libraries, using them how they come is going to result in images which are very large in file size, slowing down your website loading.
Editing and saving your image in the most appropriate size makes sure you avoid this - we will refer to image sizes in pixels. Consider a pixel as a single dot, and an image is made up of lots of dots. An image which is 1920 x 1080 pixels in size is made up of 1920 columns, each 1 pixel wide, and 1080 rows, also each 1 pixel wide - the pixel count like this is often referred to as the 'resolution'. To give context, 1920 x 1080 pixels is the resolution of a 'HD TV', so large and 'high definition'.
If an image will only be shown at a small size on screen, there is no need to have the image sized at e.g. 1920 x 1080 pixels (2,073,600 pixels) - perhaps a resolution of 480 x 270 pixels would be better (a total of 129,600 pixels). The smaller 480 x 270 images is 16 times smaller than the 1920 x 1080 image.
- Choosing the right file type:
When you save the image, we recommend using JPG/JPEG for any image which doesn't have any transparency involved, which would account for almost all photographs and similar images. When saving a JPG, most image editing software will let you alter the quality of the image - our suggestion is to use a quality of no more than 80%, and if you can't tell the difference with your eyes, taking it lower will result in an even smaller file size.
If an image has some parts that are transparent, then PNG is best in most cases, however for images without transparecy involved, PNG will nearly always result in an image larger in file size than JPG.
Be aware that often, images sourced from some stock image websites may contain lots of meta data that can result in a much larger file size than you need - we find that when editing the image, copying and pasting it into a blank image will remove all of this data and when saved, can result in a massive file size reduction.
- Naming your image:
This one is important - search engine image searches are growing in popularity, and even in non-image searches, search engines will use the names of your images to add to it's decisions on how relevant your page is to those people searching.
By not naming your images in respect of search engine optimisation, you are missing out on both improved SEO and the potential for increased numbers of visitors to your website. An image named 'slider1.jpg' gives no indication to search engines as to what the image is about, and does nothing to affect the overall relevance a search engine will give to your page. However, if your image is named to reflect what it is and what your website is about, it adds an extra benefit to your website and SEO - perhaps calling the image 'how-to-optimise-your-images-for-seo.jpg' would be more useful for this blog post and it's search relevance.
- Setting the ALT tag:
Whether a website uses hard-coded HTML or is built on a content management system such as WordPress or Joomla, the majority of ways an image is added to the page allows the 'alternative' tag to be set. The ALT tag is a sentence you can assign to the image which is not visible to a webpage viewer, but is visible to search engines and is also used by screen readers to allow a web page to be more accessible to visitors with impaired vision.
Setting this in line with the image content and your website purpose further increases your search relevance and also the accessibility of your website content.
The best use of image size, naming and meta data is relevant to all types of website, whether informational or e-commerce based. If your website has content which people may search for by images alone, getting this all correct could be even more useful to your business.
Given how easy it should be to website designers to resize an image, save it in the correct format, name it suitably and set appropriate ALT tags, there is no excuse at all for this not to be done.
How can I check if my website designer has named my images well?
Most desktop browsers, such as Google Chrome and Microsoft Edge allow you to hover your mouse over an image, click the right mouse button and choose the 'Open image in new tab' option.
This will load the image in a new tab and let you see the image name - hopefully it's called something useful and relevant to your website and services, but if not, and search results are important to you, why not get in touch with your web-design company and ask them to make some improvements.
If you'd like us to undertake a review of your website and how it's performing, get in touch and we'll be happy to discuss how we can help.