How do image optimisation and alt text help SEO?

Image optimisation helps SEO by making pages faster, easier to crawl, and more usable, which can improve search visibility and engagement. Alt text helps SEO by giving search engines context about what an image shows, while also improving accessibility for people using screen readers.

How image optimisation helps SEO

• Faster page load times: Compressed and properly sized images reduce page weight, which can improve user experience and performance signals.
• Better indexing: Clear file names, image formats, and surrounding text help search engines understand the image and page topic.
• More opportunities in image search: Well-optimised images are more likely to appear in image results and bring additional traffic.
• Improved accessibility and engagement: Faster, clearer pages tend to keep users on the site longer, which supports overall SEO.

How alt text helps SEO

• Provides context: Google recommends alt text that is useful, information-rich, and relevant to the page content.
• Helps search engines interpret images: Alt text tells search engines what an image represents, especially when the image itself cannot be read directly.
• Supports accessibility: Screen readers use alt text to describe images to visually impaired users, which improves usability and can indirectly support SEO.
• Avoids keyword stuffing: Best practice is to describe the image naturally and include keywords only when they fit the context.

Practical tips

• Use descriptive, concise alt text for meaningful images.
• Leave alt text empty for decorative images.
• Compress images and use modern file formats.
• Use relevant file names, captions, and surrounding text to reinforce image context.

If you want, I can also give you a short image SEO checklist for a website or blog post.