Search engine optimization (SEO) is essential to ensure your website's visibility and attract more visitors. One of the most overlooked aspects of search engine optimization (SEO) is image management. By properly optimizing your site's images, you can significantly improve your search rankings and provide a faster, more enjoyable user experience. In this article, we'll explore best practices for optimizing your website's images to improve your SEO.


Choosing the right image formats


Choosing the right image format is crucial to ensure good quality while reducing file size. The most commonly used image formats are JPEG, PNG and WebP. Each has its advantages and disadvantages:

  •  JPEG: This format is ideal for images with many colors, such as photographs. It offers good compression and acceptable image quality (1).
  •  PNG: This format is best for images with uniform color areas, such as logos or screenshots. It also supports transparency (2).
  •  WebP: Developed by Google, this format offers superior compression for both lossy and lossless images, as well as support for transparency. It is compatible with most modern browsers (3).


Compressing images


Image compression is essential to reduce the size of your images and speed up the loading time of your site. There are several online and offline tools to compress your images without sacrificing quality, such as TinyPNG (4) and ImageOptim (5). You can also use WordPress plugins such as Smush (6) or EWWW Image Optimizer (7) to automatically compress images when they are uploaded to your site.


Using adaptive images


Adaptive images are images that adapt to the user's screen size. They allow smaller versions of images to load for smaller screens, improving load times and user experience. To implement adaptive images, you can use the HTML tag "srcset" and "sizes" (8) or WordPress plugins such as WP Retina 2x (9) and Adaptive Images (10).


Optimize alt and title attributes


The "alt" and "title" attributes of images are important for SEO, as they help search engines understand the content of the image. The "alt" attribute should briefly describe the content of the image, while the "title" attribute can provide additional information. Be sure to include relevant keywords in these attributes, but avoid keyword stuffing (11).


Use descriptive file names


The file name of your images should be descriptive and contain relevant keywords. Search engines take file names into account when indexing images, so by using descriptive names, you can improve your SEO (12). For example, instead of using a generic file name like "IMG_1234.jpg", opt for something more meaningful like "smartphone-ecran-4k.jpg".


Structure your images with semantic HTML tags


Using semantic HTML tags to structure your images helps search engines better understand their context. For example, using the <figure> tag to frame an image and the <figcaption> tag to add a caption can improve the readability of content by search engines (13).


Manage image caching


Image caching allows you to store copies of images on the user's browser, thus reducing loading time on subsequent visits to your site. You can configure image caching by modifying the HTTP headers "Cache-Control" and "Expires" on your server (14). WordPress plugins such as WP Super Cache (15) and W3 Total Cache (16) can also help you manage image caching.


Use a content distribution network (CDN)


A CDN is a network of servers distributed around the world that stores and distributes your site's files, including images. By using a CDN, images are served from the server closest to the user, which reduces load times and improves the user experience (17). Popular CDN services include Cloudflare (18) and Amazon CloudFront (19).



Optimizing your website's images is a key element to improve your SEO and provide a fast and pleasant user experience. By following the best practices presented in this article, you will be able to effectively optimize your website's images and thus improve your ranking in search results.


  1. JPEG -
  2. PNG -
  3. WebP -
  4. TinyPNG -
  5. ImageOptim -
  6. Smush -
  7. EWWW Image Optimizer -
  8. Srcset et sizes -
  9. WP Retina 2x -
  10. Adaptive Images -
  11. Attributs alt et title -
  12. Noms de fichier descriptifs -
  13. Balises HTML sémantiques -
  14. Mise en cache des images -
  15. WP Super Cache -