1. Use Descriptive, Keyword-Rich Filenames
Instead of uploading a file named DSC3856223.jpg , name it using keywords. If this was a post on blue widgets I would name it blue-widgets.jpg
Some rules for naming image files... (these also apply to URLs in general)
- Always use all lowercase. Some servers treat capitals differently so Blue-Widgets.jpg may be a different file than blue-widgets.jpg. K.I.S.S.
- Use a dash "-" to denote a space. If you have spaces in your URL/file then those are converted into junky looking HTML like, %20
Before uploading an image, rename it with a clear, relevant filename that includes keywords.
2. Optimize Alt Text for Accessibility & SEO
Alt text helps search engines understand the image and improves accessibility for visually impaired users.
<img src="healthy-breakfast.jpg" alt="A bowl of oatmeal with fresh berries and almonds">3. Choose the Right File Format
WebP – A modern format that provides high-quality images at smaller file sizes.
JPEG – Best for photos and images with lots of color.
PNG – Ideal for images requiring transparency but larger in size.
4. Compress the images
We've written an entire post on How to Properly Pre-Process and Optimize Images for WordPress.
Our favorite tool for compressing and resizing is Kraken.io
5. Surround Images with Relevant Content
Google considers the text around an image to determine its relevance. Ensure your images are placed within meaningful content that supports them.
Optimizing images for SEO isn’t just about making them look good—it’s about ensuring they enhance your site's visibility, load quickly, and improve user experience. By using descriptive filenames, keyword-rich alt text, and the right file formats, you help search engines understand and rank your images better. Compressing images, leveraging responsive design, and using a CDN ensure fast load times, while structured data and image sitemaps further boost discoverability. When done right, image SEO can drive more traffic, improve rankings, and enhance user engagement.