This is part of our on-page SEO mini-series focusing on what can be done at the page level to boost your optimization efforts in organic search. In this post, we’ll be discussing images, how they pertain to SEO, and how to optimize them for search engines.
How do search engines see images?
Up until recently, Google and other search engines didn’t have the easiest time understanding images and what kind of content was contained in the image. Search engines primarily relied on things like alt text and its relation to the context on that section, along with the rest of the page content to understand an image.
These days though, Google has become increasingly more adept at understanding images. With the introduction of services like Google Lens, where you can literally search for something simply by taking a photo of it, its clear search engines are evolving at a rapid pace.
Despite the ongoing advancements, however, search engines still rely on traditional image optimization elements to understand, rank, and serve images. Additionally, they use this information to help understand the content and context of a web page.
Why is image optimization important for SEO?
Image optimization offers many different kinds of benefits to boost your SEO and should be considered an essential component of your on-page optimization strategy.
Improved site speed
Optimized images can boost your site speed, which is one of the few ranking factors Google has officially confirmed it uses when ranking websites.
Accessibility plays a huge role as part of the image optimization process. For users who are hearing or visually impaired, optimized images allow screen reading devices and other accessibility tools to properly relate that content accurately to users. Google seeks to continually improve its user experience and making websites more accessible for everyone is an integral part of that.
Improved visibility in image search
As more and more people use services like Google Lens to search for information, products, and services, not optimizing your images means you’re missing out on a huge segment of additional website traffic.
This is especially important for eCommerce businesses. Product images optimized for visual search will have greater visibility in the image search results which can translate into improved rankings, traffic, and ultimately revenue.
So what does it take to fully optimize images for search? Let’s take a look at each component below.
Steps for Optimizing Images for SEO
Image file size
Oversized images can bog down your site speed. Pictures with a large file size take longer to load and many websites are designed where the content will not be displayed until the image loads completely.
Consider that if a web page takes longer than 3 seconds to load, just over half of your visitors will leave. Basically, for every second you keep your website visitors waiting, you’re losing loyalty and revenue.
As Google penalizes slow websites by ranking them lower, and with 46% of people saying waiting for pages to load is what they dislike most about browsing the web on mobile, ensuring your site loads quickly on every device is essential. Reducing your image file size can have one of the most immediate and dramatic boosts to your page speed.
Ideally, you’ll want to try and keep your images under 100kb. While this isn’t always possible, it’s a good target to try and aim for.
To resolve any oversized images, the best place is to start is by using a website crawler tool like Screaming Frog to identify any oversized images. Once you’ve identified the image locations, you can begin to make changes.
Another useful tool for understanding your site speed is to use Google’s PageSpeed Insights tool. This will let you know how your site currently performs and also offers recommendations for improvement.
You can use image-editing software to reduce the file size. Keep in mind image formats like PNG, will typically be larger than JPG files. With that in mind, it’s often best to go with the image format that offers the lowest file size. Canva is a free image editing tool you can use online and is an easy way to get started.
You can use additional tools such as WordPress plugins or apps to further reduce your image file size. Smush is one of the most popular plugins for WordPress that will help compress your images automatically.
Image alt text
Your image alt text is probably the most important element of optimizing your images to boost SEO. This is primarily what Google looks at to understand an image. Additionally, this is what screen readers and other accessibility tools will use to relate the content of the image to the users.
Image alt text is used to describe an image. It should essentially contain a brief description of the image but ideally, this is also a hot spot for important keywords so you’ll want to find a way to include them here as well.
Keep in mind, however, that you’ll want the image description here to read like natural language. Excessive use of keywords or inaccurately describing the image will negatively affect your SEO. You’ll need to find a good balance of describing the image accurately, using natural language, while incorporating keyword whenever possible.
Google uses the alt text of an image to help serve up relevant results in image search. The more strategic you can be with your alt text, the better your chances for your image ranking in visual search and the better Google is going to understand the image and how it relates to the content on your page.
When it comes to image optimization, here are some things to remember.
- Briefly and accurately describe the image
- Write in natural language
- Incorporate keywords when appropriate
- Keep text under 125 characters
- Write in all lowercase
- Avoid keyword stuffing
- Avoid the use of special characters
- Avoid overly descriptive writing
Here’s an example:
Let’s say you’re an eCommerce store specializing in women’s fashion. Some important keywords for your website might include terms like trendy apparel for women, online clothing store for women, etc. (these are super basic and generic keywords but we’ll use them for the sake of this example)
A good example of alt text for this image might look something like:
young woman holding shopping bags
This accurately and briefly describes the image but we may have more potential to incorporate keywords here. We could potentially add to this to include more of our target terms.
That might look something like:
young woman holding shopping bags wearing trendy apparel from online clothing store
Here we’ve been able to still accurately and briefly describe the image (83 characters) while incorporating our keywords (highlighted).
A bad example of image alt text would look something like this:
A young woman wearing a white dress and white sunglasses holds 4 shopping bags with different colours with a surprised expression on her face and bright red lipstick
Or an example of keyword stuffing might look like this:
online fashion for women best clothing store shop trendy apparel stylish sunglasses
In the above two examples, being over descriptive is unnecessary and offers no real value. Additionally, keyword stuffing doesn’t describe this image accurately and will negatively impact accessibility, which will negatively impact your SEO.
While the image file name doesn’t have any direct correlation as a ranking factor, following these best practices can save you a ton of headaches down the road and primes your images for any future data extraction that may become necessary.
Similar to image alt text, your image filename should accurately describe the image. Ideally, you’ll want to separate each word with a hyphen and avoid using underscores, numbers, or other special characters.
A good example referencing the image in the last section would like something like this:
This is a clean and accurate description. As each word is separated by a hyphen, it is easier for search engines to understand and distinguish each word in the file name. Additionally, if the image alt text was ever pulled from the image filename, it would still be an accurate and helpful alt text to include. Plus it helps keep your URL slugs clean, concise, and organized.
Getting into the habit of naming your images in this way will not only help your optimization efforts now but could save you headaches down the road.
This can be a bit of a tricky one as images with a higher resolution tend to have a higher file size. Google has said again and again it wants faster websites. It also recommends serving high-quality images.
With this in mind, you’ll want to find a balance between keeping a low file size while still offering images that are high enough in quality and resolution to look appealing. You may have to compromise from time to time but the main takeaway here is: don’t serve blurry or low resolutions images whenever possible.
It’s important that when you include images on your web page, they are positioned next to relevant text. This helps Google understand the context and relationship between the text and image. The more Google can understand this relationship, the more likely your images will rank in visual search and this will also offer SEO benefits to your page overall.
Use responsive images
Ensuring your website is responsive is an essential component for everyone. As users may be visiting your website from a variety of devices, ensuring your images will respond and adjust properly to each device is a necessary aspect of image optimization. Basically this means that the image will preserve its resolution, dimensions, and placement across all devices.
Add structured data
Structure data markup helps to provide additional details about an image to give Google as much information as possible to best understand the image. It can help provide more details like whether this image is a product, recipe, etc.
When an image has proper structured data markup, it becomes eligible for Google’s rich results which helps your images stand out in the sea of pictures in the search results page. When this happens, photos can include things like price, available stock, etc. Plus Google will also include a prominent badge on the images for improved visibility.
Ensure you’re following the structured data guidelines to avoid any errors which could affect your SEO.
Use an image sitemap
Your images are an important source of information for Google in relation to the content on your site. Using an image sitemap helps provide Google with additional details it may have missed when crawling your website. You can learn more about using an image sitemap here.
Image optimization plays a vital role when it comes to page speed, accessibility, and improving visibility in image search results. Optimizing your images should be considered an essential component of your on-page SEO.
When completed properly, this can greatly improve your exposure in regular and image search results and it helps Google better understand your website. For eCommerce businesses, it can dramatically increase product exposure, especially when combined with structured data markup. Optimizing your images site-wide can significantly boost page speed which directly relates to improved SEO and overall better user experience.
Looking for advanced strategies to boost your SEO? Get in touch with our team of search engine optimization experts for a free site audit and consultation today!