How to Optimize Images for SEO in Web Design

A great image can bring an otherwise dull website page to life. But if you’re looking to grow your website traffic, your images should also serve another purpose: optimizing your site for search engines. If you’re not an SEO professional, you probably need some guidance on image optimization.

There are a lot of small ways you can optimize your website images for SEO. If you use all of these tips together, they can really add up to help your site rank higher in search results and attract more potential customers.

1. Use Enough Images

There’s no definitive answer to how many images you should have on your site. That said, website visitors generally find images more visually appealing and engaging than text alone, and their engagement affects your search engine placement.

You should have enough images to support the other content on your site and showcase your products. For text-heavy articles and blog posts, you can start with a guideline, like one image for every 250 words. It often makes sense to add more images when you’re discussing highly visual topics.

2. Choose Helpful Images

The best images for SEO are also the ones that are most helpful to humans visiting your site. Stock images (when used with the necessary permissions) have their place, but unique images like these often have the most SEO value:

• Photos of your products.
• Charts that compare your products to each other or to competitors’ products.
• Screenshots that show how to use your app.
• Icons that help users quickly understand product features or find what they’re looking for on your site.

3. Upload Images in the Right Format

Different image formats have different purposes. For logos and icons, SVG is usually the best option because you can resize it without quality loss and manipulate it with JavaScript or CSS. For other kinds of images, you have several options:

• WebP creates fast-loading images, including images with transparency or animation.
• PNG is another good choice for images that contain lots of details, text, or a transparent background.
• GIF is a popular format for simple animations.
• JPEG is a good choice for most other images.

If the image you want to use isn’t in the right format, there are many tools you can use to convert it to another format.

4. Pay Attention to Image Size

Image dimensions should be large enough for visual quality but not so large that they might take a long time to load. If your website layout uses container elements, your images shouldn’t exceed the maximum size of the container. Even without that restriction, website images typically shouldn’t be wider than 2,500 pixels.

You may have a website plugin that adjusts image sizes, such as WordPress’s Resize Image After Upload plugin. If not, you can use Photoshop or another image editing/compression tool to resize your images.

5. Use Descriptive File Names

Search engines use image file names to understand what they depict. Choosing a descriptive but concise file name can give your image an SEO boost. 

Ideally, image file names should be less than 50 characters with lowercase letters, no special characters, and hyphens instead of spaces to separate words.

6. Make Images Responsive

Responsive images automatically adjust based on the user’s screen size. Using responsive image scaling makes images the right size for whatever device your site visitor is using, whether it’s an iPhone mini or a 22-inch desktop computer. The technique also reduces loading times on smaller devices.

If your website builder doesn’t use responsive image scaling by default, you can use a plugin, talk to a web developer, or ask an SEO agency for help.

7. Add Alt Text For Functional Images

Alt text is a written description that replaces an image when someone can’t see it. Text-to-speech tools read them aloud to help visitors with visual impairments understand the content, and the text also appears if your page doesn’t load properly.

Search engines also use alt text to understand what an image depicts. Adding brief but descriptive alt text to non-decorative images like charts can improve the website experience and also help with your SEO.

8. Consider Captions

Captions are a great way to give website visitors more context about an image, especially when the image shows a complex diagram or unusual event. Search engines gather information from captions as well as alt text, so it’s a good SEO practice to add captions whenever they would help your human visitors. 

Don’t add captions just for the sake of having captions, though. That will lead to a worse user experience.

9. Use Lazy Loading

Lazy loading makes a website page’s initial load time faster. This option avoids loading content below the fold until the user scrolls down to see it.

If you’re familiar with HTML, you can set up lazy loading by adding the loading=”lazy” attribute to image tags. It looks like this: <img src=”image-file-source.png” loading=”lazy” alt=”Image alt text”>

10. Create an Image Sitemap

An image sitemap is a type of XML sitemap that is specific to images. It lists all the images you want search engines to crawl and index. If you’re not sure how to create an XML sitemap, you can start with a sitemap generator tool or ask a web developer for help.

11. Enable Browser Caching

Browser caching lets the visitor’s browser store logos, images, or other files for a certain period of time. Since the images are stored locally, they load faster the next time the person visits your site. Browser caching also reduces the bandwidth and number of requests your server needs to handle.

12. Add Schema Markup

Schema markup, AKA structured data, gives you a better chance of securing rich snippets. Rich snippets are search results with extra elements that grab users’ attention, such as images displayed alongside a preview description.

Google offers a guide to the different types of schema. If you need help adding schema markup, you can work with an SEO specialist or web developer.

13. Use a Content Delivery Network (CDN)

Internet images don’t appear out of nowhere. They’re hosted on a server in a specific physical location. Some servers take longer to transfer image data than others, depending on the technology they’re built with and how geographically close they are to a user.

A CDN lets you host images on multiple servers around the world. That way, the image data can travel from the fastest server for each website visitor.

14. Use Open Graph Meta Tags

Open graph meta tags help search engine users see the best possible preview of your pages when you share them on social media sites. You can specify an image, type of page, and the image you want to show up in the preview.

Some website builders let you customize open graph meta tags. If it’s not an option by default, you can also use a plugin or ask a web developer for help.

Image Optimization as Part of a Larger SEO Strategy

Image optimization is just one of the many ways you can boost your website’s SEO. The steps we’ve described above work best when you also have a good site structure, apply on-page SEO techniques, and use effective content practices. Off-page SEO tactics like link building can also make a big difference.

If you need help with your SEO efforts, you can hire an SEO marketing agency like Rocketship to help. Our team has the time, resources, and expertise to help your website attract more traffic and grow your business.

Schedule a consultation with Rocketship for expert SEO assistance.