Ever since the Google Core Web Vitals and the ranking factor loading speed, you should take the topic of image SEO seriously. There are various ways to optimize your images in WordPress. Here is our overview of the most important tips and tools.

Images, photos, infographics and other illustrations have become an integral part of writing high-quality articles. However, they not only loosen up the text or clarify some processes better than words could. In fact, with the right approach, you can make your website even faster and easier to find in search engines.

In addition, both Google itself and the competitors of the smaller search services offer an image search. Searchers can use it to find your website. So why miss out on the great opportunity of image SEO with WordPress?

How does image SEO affect your visibility?

Let's start by looking at SEO for images independently of WordPress. If you include high-quality images in a post, you can attract the attention of many visitors. However, it's not just search engines that play a role here. If you prepare your images accordingly, this can influence various aspects.

Firstly, you increase your visibility considerably, because your images themselves can of course be found in search engines - not just your texts. Someone could find their way to your website as a result. Would you like a small example?

The image search on Google

I use Google Search and enter the term "pasta recipe". But as I don't just want a recipe in text form, I switch to the image search. Beautiful pasta dishes are now displayed there:

I really like the third picture from the left. The noodles look really tasty. For this reason, I click on the picture and then land on the corresponding page, which has made an effort with the image SEO.

So if you use search engine optimization for images correctly, you can reach many more people. But this is just one example of many.

The social media

Because images not only influence search engines, but also people. And where are people active every day? On social networks such as Facebook, Twitter, Instagram, Pinterest, LinkedIn & Co.

Let's take the above example a step further. Let's say you run a food blog. How great would it be if visitors who found your recipe shared the corresponding post on social media? So they click on the share button for Facebook, for example. And if there is no proper post image or it is not properly integrated, they will see a very sad image, namely none.

In this form, a post does not invite people to click or share it. On the contrary, the post will be lost in the vastness of the social network - and will not be taken into account. Only if a suitable image is displayed next to the text does this significantly increase the attractiveness:

For a food blog, for example, you shouldn't use images that mainly consist of text content. You expect the finished recipe there. However, I still choose text images from time to time. I'll explain why in the next section.

Where to source high-quality images?

There is often a small problem with high-quality images. A problem of a legal nature. You will certainly know that you are no longer allowed to simply use Google Image Search to copy images. These are protected by copyright. So you now have the following options:

• Use paid platforms
• Use license-free images
• Create or photograph images yourself

Not every website has a budget that allows it to purchase expensive stock images. For example, from Fotolia or Shutterstock. With royalty-free images (such as those on Unsplash or Pexels), there is a risk that they were not always uploaded by the creators. There are even reports of sophisticated scams that can end up being expensive.

Platforms such as Pixabay do indicate the possible uses. But there have already been legal disputes that have ended to the detriment of website owners. So my tip: Take a screenshot of the license information when downloading. For the reasons mentioned above, I have decided to use images I have created myself, where I work a lot with text content. I can publish these with a clear conscience and without any legal consequences. For a website that relies much more on images, you may want to take a different approach.

Use images SEO efficiently

How can you optimize images for SEO? First of all, I would like to give you some common procedures to help you achieve more visibility for your images or your website. In the next section, I'll show you how to implement these processes for your image SEO with WordPress. After all, installing WordPress plugins is not always the solution to the problem.

Non-optimized images worsen your ranking

Most people who own a website think that optimizing images for search engines is all about being better displayed in searches or in social network previews. But this is not the case. Images also need to be improved with regard to the Google Core Web Vitals mentioned at the beginning. This is about the usability of your website, see this article on the new ranking factor. In addition, your target group is increasingly surfing the internet on their smartphones.

So if websites have large and non-optimized images, the website loads slowly and the user has to be patient. But who wants to wait for non-optimized images? The result will be a poorer Google ranking from May 2021.

The image size

You should therefore try to keep the image size as small as possible when creating it without losing image quality. If you create the images yourself, you can control this using the image editing program. Adapted formats for the website (i.e. width and height in pixels, for post images depending on the WordPress theme) have also proven to be very efficient here. Then WordPress does not have to scale the images unnecessarily.

If you have taken a picture with a professional camera, it could contain thousands of pixels. The content of a website is usually limited in width. It would therefore make sense to upload the image in this width only. Especially as it can then quickly be up to several MB in size, which is no longer necessary in modern web design - and kills your loading times.

Format & Compression

The format of your images is often related to compression and a few other factors. For example, while images with transparent elements tend to be saved as PNG, the JPG format is more suitable for colorful graphics.

Whereby JPG allows a higher compression and can therefore significantly reduce the file size. However, the quality of the image suffers a little. There are now AVIF and WebP for WordPress, other formats that are intended for the future. They deliver even better results.

Fill in metadata correctly

Most search engines still rely on so-called meta data. This is basically information that the website stores in the source code so that the search services can assign the data.

Google, as the largest provider, is technically very advanced and does not require the meta data in as much detail as the smaller search engines. Nevertheless, I would always add it. It doesn't harm your website and gives you the chance to be found with additional sentences and words.

Incidentally, the meta data has nothing to do with the name of the image files. You should name them eloquently - i.e. with a description of the content - before uploading them. Let's return to the example of the food blog. A pasta dish with minced meat sauce should therefore be called something like "pasta-dish-with-meat-sauce-for-cooking.jpg". Meta data for images is simply inserted in the source code as HTML - WordPress does this for you if you add the relevant information when uploading the images, more on this later.

The source code for a properly populated screen could look like this, for example:

<img src=“domain.de/Nudel-Teller-mit-Hackfleischsauce-zum-Kochen.jpg“ alt=“Nudel Teller mit Hackfleischsauce“ title=“Nudel Teller mit Hackfleischsauce“ />

The alt tag is an alternative (text) label that can be displayed if the image is not displayed. For example, due to an outdated browser or a broken link, etc. However, it is also important for people who use a screen reader. This is another reason why you should pay attention to speaking content (accessible websites). The image title tag (not to be confused with the title tag of the website!) is used to display further information about the image on mouseover.

Image optimization outside of WordPress

If you create or edit your images yourself using an image editing program such as Gimp or Photoshop, then you should not use a solution in WordPress. It is easier and saves resources to optimize directly in the program. Here is an example from Photoshop:

The original file of the post image for this text was originally over 4 MB and became a JPEG file with 340 KB and an image size of 2560×1440, with hardly any visible restrictions. Depending on the image, it is partly similar with PNG.

If you now reduce the resolution of the images, i.e. adapt them to the WordPress theme, you can create even smaller file sizes. In my own blog, for example, the cover images have a size of 720×360 pixels. This depends on the theme and may look different for you.

Find out image size in WordPress

A little note about the image sizes in WordPress. You can easily find these out, but they have nothing to do with the media specifications in the general WordPress settings:

Here you can set the standard sizes used by WordPress. When uploading, WordPress creates additional images in these sizes. However, this does not change the sizes as they are displayed in your WordPress theme.

Some themes give you the option to do this in the settings, others do not. You can then simply go to your website in the browser and take a closer look at an image - such as the post image - by right-clicking on it. You will then find the sub-item "Show graphic info".

If it says under "Dimensions" that the image has been scaled to a different size, you would actually have to adjust the corresponding images again. This is because the WordPress theme specifies a different size at this point than the one you have cropped.

Define meta data in WordPress

Images play an important role in search engine optimization, not only because they enhance texts. Rather because they make you visible. And because you can show Google & Co. what you are writing about on your website.

Think of images as a necessary addition to the content. In order for the search engines to recognize the potential, you need the aforementioned meta information. As already described, you should give the images an SEO-optimized file name before uploading them. Therefore, name the images very precisely. The title should reflect what can be seen in the image.

WordPress allows you to enter the metadata for images directly when uploading. However, I recommend that you do not add the images directly when writing, but go via the media gallery. To do this, simply click on Media -> Add file on the left-hand side of the WordPress backend. You can then select and upload an image from your PC using the button of the same name at the top.

After the successful upload, an "Edit" button appears, which you click on. WordPress will then open the media file and show its most important information. You can now fill in the fields marked in red in the image:

If you add the image later in the Gutenberg Editor, it will automatically receive the corresponding meta information. However, please avoid using images more than once. Instead, upload them again with a new file name and new metadata. This is because these details are usually optimized for a specific post.

Lazy loading for images in WordPress

In order to achieve a website that is as fast as possible and complies with Google's new Core Web Vitals, only the content that is currently required should be loaded. Images that are displayed at the bottom of a long article do not need to be displayed or loaded at the beginning.

This is where lazy loading comes into play. In other words, the delayed loading of images that are not in the "above-the-fold" area - the area that the reader can see directly. While this function was previously only possible with certain WordPress plugins, for example with Autoptimize or WP Optimize (only from Premium), those who have at least WordPress 5.5. installed can rejoice.

This is because lazy loading is now already taken into account in the core of the code. Since WordPress 5.7 even lazy load for iFrames. If you have an older version installed, you should definitely update it.

WordPress hosting image caching

You can achieve a significant increase in performance in WordPress by using a cache. A distinction can be made here between browser caching, which only stores certain files on the end device, and server-side caching. With the latter, the dynamically generated content from WordPress is also made available in static files on the server.

This means that the website does not have to access the databases every time it is called up. This is because such accesses increase the loading speed on the one hand and the load that your server has to bear on the other. This can be an effective way of saving resources, especially for large websites with many visitors.

The disadvantage: You cannot have certain page content created dynamically. For example, if you use various advertising banners, you would have to exclude them from caching. Or accept that they do not change in a post. You also have to take certain exceptions into account for online stores with WooCommerce so that the ordering process works correctly.

In addition to very extensive plugins such as WP Rocket, which is subject to a fee and offers many settings, you can also implement caching with free plugins such as WP Optimize or W3 Total Cache. Raidboxes offers its own server-side caching in its WordPress hosting. The NGINX cache there becomes active before WordPress takes over. This allows websites to be delivered without slowing down WordPress. Another advantage: you no longer need a WordPress caching plugin and don't have to worry about complex settings.

Conclusion on image SEO with WordPress

Optimizing WordPress in terms of images can really pay off. Not only will you increase your rankings, but you can also attract additional traffic. On the other hand, it does take some work. Especially at the beginning, when you're still new to the topic. Over time, however, it will become easier and you will achieve strong results.

Especially because Google is paying more and more attention to loading times, it makes sense to pay attention to more than just the meta data. Provide the images in the correct file format, compressed and with exact sizes. Your visitors will thank you because the page will quickly provide the desired information. If the content is also right, nothing stands in the way of your success.

More articles about SEO on wp unboxed that will help you with Google & Co:

• Yoast vs Rank Math: WordPress SEO plugins in comparison
• 8 steps to an SEO audit - instructions for websites and agencies
• Keyword research for SEO success: step-by-step instructions
• WordPress SEO: Optimizing texts for search engines