SEO for images: this is how to optimise images for better findability

Images not only make a website more attractive, but also play an important role in search engine optimisation (SEO). A well-optimised image can make your website load faster, rank better in Google Images and attract additional visitors. But how do you make sure your images contribute to better SEO?

Why is SEO important for images?

Search engines like Google use images to better understand the context of a page. A well-optimised image contributes to:

• Faster loading times and a better user experience
• More likely to appear in Google Images
• Higher SEO score of the page
• Better accessibility, e.g. for people using screen readers

In addition, AI is getting smarter at recognising visual content. Tools such as SearchGPT help analyse searches and can influence how images are indexed and displayed.

Best practices for SEO image optimisation

1. Choose a descriptive file name

An image named IMG1234.jpg tells search engines nothing. Instead, choose a file name that describes what can be seen in the image. For example:
✅ wooden-dining-table-with-steel-legs.jpg
🚫 photo1.jpg

Or for a product image:
✅ leather-work-backpack-with-zipper.jpg
🚫 productfoto-new.jpg

This allows Google to immediately understand what the image is about and increases your chances of ranking well in Google Images.

2. Add alt text

Alt text is important for both SEO and accessibility. It describes the image for search engines and for people who cannot see the image. A good alt text is:

• Short and descriptive (Wooden cabinet with black metal handles)
• Not stuffed with keywords
• Useful for users and not written purely for search engines

3. Use the right file format

Images should look good but also load quickly. The best formats are:

• JPEG - Suitable for photos with lots of detail
• PNG - Handy when you need transparency
• WebP & AVIF - Modern formats combining high quality with smaller file size

JPEG and PNG are the most compatible, but WebP and AVIF are increasingly used because they help reduce the loading time of a website zonder quality loss.

4. Compress your images

Large files make your website slower, and a slow website does not rank as well in Google. Use tools like TinyPNG or Squoosh to reduce file size zonder that the quality deteriorates.

5. Make images responsive

Visitors use different devices, from smartphones to desktops. Use srcset in the HTML to ensure that browsers choose the right image depending on the screen size.

6. Add structured data

With Schema Markup (as the ImageObject schema) you give search engines additional information about an image. This increases its chances of being displayed in rich results.

7. Use an image sitemap

A sitemap specifically for images helps search engines better index your visual content. This is especially useful if images are loaded via JavaScript. Add an image sitemap via Google Search Console.

8. Avoid text in images

Google can recognise text in images, but not always accurately. Put important text in HTML rather than in an image so that search engines index it correctly.

9. Apply lazy loading

Lazy loading ensures that images only load as soon as they come into view. This improves loading speed and ensures a better Core Web Vitals score.

10. Make sure your images are indexable

If an image is blocked via robots.txt or a noindex-tag, then Google cannot find them. Check via Google Search Console whether your images are indexed correctly.

Additional SEO factors for images

Does the title of an image affect SEO?

The alt text and filename are more important than the title of an image. The title (title-attribute) can provide additional context, but has less influence on ranking.

Do onder titles and descriptions help with SEO?

Yes, onder titles and descriptions can contribute to SEO by providing additional context. This is especially useful for blogs and extended articles in which images play a key role.

Are stock photos bad for SEO?

Not necessarily, but original images have a greater advantage. Unique images improve the user experience and increase the chances of a higher ranking.

More than just an ALT text

SEO for images is more than just adding an alt text. By paying attention to file names, formats, structured data and optimisation techniques, you increase the chances of your images displaying well in search results. This way, you not only help search engines, but also your visitors to a better experience.

Want to learn more about SEO and how to optimise your website? Check out our SEO training and find out how to increase your online visibility.