Images are an important part of any website and there are many opportunities to optimize images for SEO. Images are one of the most overlooked aspects to on-site SEO and they can make a huge difference to the overall SEO score of your website. Moreover, good images can even bring traffic and backlinks on their own, so it’s imperative that images are fully optimized.
Filenames, Alt Tags, Titles and Captions
Although IT giants such as Microsoft have been investing a lot of money in image recognition, the truth is that computers just aren’t very good are seeing what an image is about. Therefore, you need to tell them about the image wherever possible.
Use your keywords in the file name when saving images. If your main keywords are “best dog walking leads”, then you might want to use the following filename:
Similarly, you can enter the same keywords for the alt tags which display if the image can’t be displayed. You can also use them in the title which is displayed when the mouse hovers over a picture and they can also be used for captions which are usually displayed under the picture.
However, if you have a number of images on a page, you shouldn’t use the same keywords for each image. You do need to make filenames, alt tags, titles, and captions look natural, so don’t stuff too many keywords in here because it could lead to an over-optimization penalty and a lower position in the search engine rankings.
You should use your main keywords on your first image and then use a combination of related keywords for the rest of your images.
Page loading times can also affect your search engine rankings. Google publicly acknowledges that page speed is used as part of their ranking algorithm, so it’s important that you keep image file sizes as small as possible as this reduces page load times.
Never use CSS or HTML to resize larger images. Browsers will still need to load the original photo and then resize it according to your CSS or HTML code. Instead resize the actual image to the size that you require before uploading it to your website. This will result in much smaller file sizes.
Secondly, you can also reduce the quality of an image in order to reduce file sizes even further. With software such as Photoshop, you can change the quality of an image. The lower the quality means the lower the file size. You can select the lowest possible quality required and reduce loading times even further.
Finally, you can then use a free online image compression service such as TinyPNG to compress images and get them to the lowest file size possible. It’s possible to have a full HD (1920 x 1080 pixels) with good quality at less than 200kb.
Sitemaps are used by websites to show search engines exactly what content is located on their website and where to find it. In terms of SEO, this information is invaluable for search engines and it’s recommended that you create a sitemap for your images and submit it to Webmaster Tools.
If you’re using WordPress to build your website, there are many free plugins which can do this for you. Two of the most popular plugins are “Yoast SEO” and “Google XML Sitemaps”. Both will create a sitemap for you and ping the search engines to tell them that you’ve updated your website.
There’s some discussion about whether or not social signals from websites such as Facebook and Twitter can help with rankings or not. Either way, social signals certainly can’t do any harm to your SEO score and they can also bring some traffic.
Websites such as Facebook use OpenGraph to pull the correct images from a website to be shared on their social network.
To encourage sharing on your website, make sure that you use OpenGraph meta properties in the tag of your website. For example:
This tells Facebook which image they should be using when visitors share your page on their social network.
Twitter has a similar method, but they use Twitter Cards instead of Open Graph. Again, Twitter Cards should be placed in the section of your page. An example of a Twitter Card is:
This article covers four ways to optimize images for SEO. As a minimum you should be reducing file sizes where possible and optimizing all titles, descriptions, alt tags and captions. As social media continues to play a role in SEO and will likely continue to do so, it’s also a good idea to ensure that you prepare your images to encourage as much sharing on social media websites as possible.