Images have always been huge online. They help to keep the content varied and visually appealing. But managing images on your WordPress website involves a fair amount of work – from technical optimization to library management, and from optimizing for SEO to integrating with a CDN. In this post, we’ll keep our focus on one aspect of managing images – creating SEO friendly images for WordPress. Don’t forget, images are not only an integral part of most websites, they can also generate traffic from image based searches.
To get to the top slot in a Search Engine Results Page (SERP), our webpages need to be easily found by Google, the dominant search engine on the internet. As early as 2010, Google made it clear that site speed is one of the factors that it would consider while ranking a webpage. So, if you’re serious about improving your SERP rankings, you’ll realize that you’ve got to pay attention to site speed.
Optimizing Images for Search Engines
Images files are typically byte-heavy and load more slowly than other resources like text and HTML. However, you can optimize images so that they are no longer a drag on your site speed and can, in fact contribute to your site’s SEO.
First off, make sure you’ve got top quality images that support your content. Next, to ensure that search engines can find these images and serve them up to your readers, consider the following technical and text-related optimizations.
Technical optimization
File Format
Two image file formats are common on webpages – PNG and JPG. The general rule of thumb is, for flat images or anything that’s vector based (such as logos, illustrations, fonts or shapes), go for a PNG format. The reason being that the PNG format can compress the file without sacrificing too much quality for such images. For all other images, including photographs, opt for JPEG formats.
While saving the files, select the ‘Save as a Progressive JPG option’, so that the files load layer by layer, without waiting for the entire file to load. Also, there’s no need to pick a high DPI (Dots per inch), 72 is good number for web pages.
If you wish, you can also use external services like TingPNG to reduce your file size without any great loss in quality.
Reducing File Size Before Uploading
WordPress’ inbuilt thumbnail feature can automatically create 3 different sizes of the images you upload – thumbnail, medium and large.
Many bloggers simply display the large image option and link it to the original full size image that they upload. That’s not really efficient because, while WordPress reduces the size of the images, it does not compress them. It’s best to optimize your images before you upload them.
Using graphic software like Photoshop or GIMP, convert image files to chosen format and select the lowest setting possible. A larger resolution means a larger file size, so you’ve got to strike a balance between resolution and file size for optimal loading speed. Often, you’ll find that the software you use can compress the files to half their size, without noticeable difference in quality. Many tools like ImageOptim and RIOT can help to optimize the images in batches.
You can also optimize the images after uploading to your site, with the help of a plugin like Smush. Once you set a maximum height and width, the images will all be scaled down, compressed, and stripped of all unnecessary data like date, time or device. If you do not want to use an external server to optimize your images, you can choose a plugin like EWWW Optimizer.
Using CDN
A Content Delivery Network is a wide network of servers that serves content to visitors from a location that’s closer to them. This ensures a faster response time. WordPress users can activate the Photon module of the Jetpack plugin. It uses the WordPress.com cloud to cache images from the posts and pages of your website. It can fetch, resize and serve up any .png, .gif or .jpg image.
Text-Related Optimizations
When you upload images to a WordPress post, you get the option to fill in some image specific fields:
- Title
- Caption
- Alt Text
- Description
You’ll find these fields when you click the “Insert Media” button on the Post Editor, and select / upload an image. You can choose to simply go along with the default settings. But that’s really not a wise thing to do for better search engine visibility.
The field you should definitely not skip is the Alt text. It helps search engines like Google understand what the image is about and why it is relevant to the content. The Alt text doubles as a placeholder, and so, it’s important to fill in the dimensions of the image. Moreover, screen readers use them to synthesize voice overs for the visually impaired.
The Alt text should ideally describe the image so that a reader can understand what should appear in that space, even if the image fails to load. If you can include keywords organically in the Alt text, that’s wonderful. However, do not resort to keyword stuffing as Google doesn’t take kindly to it.
The caption will appear below an image and the name you give your image file will reflect as the title that can show up on the tooltip on some elements. While not terribly important, they may add SEO value to a local business, if filled in with care. Geotagging and including Name, Address and Phone number (NAP) in the image content of a local business’ website may also boost local SEO.
The Yoast SEO plugin, checks your images for SEO compliance and a plugin like SEO friendly Images can add Alt tags and convert image file names to ALT tags. To improve your chances with Google, you can also generate an image sitemap of your blog and submit to Google. Yoast SEO also supports image sitemap, else you can use Udinra All Image sitemap.
Other Optimization Measures
There’s more you can do to optimize your images – you can ensure proper linking of images, import external images to your website, prevent hotlinking to your images, and embed links to videos on video sharing services (for video files), and more.
Final Words
Optimizing your images will improve site speed and user experience, reduce bandwidth, and may well push you up a few notches in SERP rankings. For more reading on the subject, you may wish to look up Google’s Image Publishing Guidelines.
Here’s a handy shortlist for creating SEO friendly images:
- Choose high quality relevant images.
- PNG for flat images, JPG for everything else – a DPI of 72 and saving as a progressive file is optimal setting for webpages.
- Compress image files before uploading using graphic software or external services.
- Use CDN, wherever required.
- Add Text details, specially Alt text, to image files.