Optimisation des Images pour le Web : Dimensions, Poids et SEO

Alexandre Teillet
Webflow tips

The web is a visual space. Every day, billions of images are uploaded, shared, and viewed online. But did you know that the size, weight and format of these images can have a significant impact on the performance of your website and your SEO? In this article, we'll explore why it's critical to resize, optimize, and adjust the weight of your images for the web.

Why resize images for the web?

When you upload an image to your site, it takes up a certain amount of space. The bigger and heavier the image, the longer it takes to load. This can significantly slow down your site speed, which impairs the user experience and can also affect your SEO ranking. By scaling your images and adjusting their weight, you can improve the performance of your site and ensure a smooth experience for your visitors.

The impact of image weight on site speed

Image weight refers to the size of the file in kilobytes (KB) or megabytes (MB). A heavy image can significantly slow the loading time of a page. For a fast website, it is recommended to keep the weight of the images as low as possible without compromising their quality. Ideally, an image for the web should weigh between 50KB and 500KB, depending on its size and use.

How do you optimize images for SEO?

  • Compress your images : Compression reduces file size without compromising file quality. Tools like Tinypng can help you compress your images without losing quality.
  • Rename your files : The name of your image file can help search engines understand what it is. Instead of "IMG1234.jpg “, name it" pomme-rouge.jpg.”
  • Use the alt text tag : This tag describes the image to search engines and screen readers for web accessibility. Make sure each image has a relevant alt tag.
Utilisation des balises alt texte dans webflow
Using alt text tags in Webflow

What are the no-code tools to resize images?

There are several no-code tools that make it easy to resize images for the web. Figma, for example, is a design tool that also allows images to be resized and exported. Tinypng or Squoosh, as mentioned earlier, is great for compression.

Ideal dimensions and weights for the web

  • Favicon : A favicon is the small icon that appears next to your site title in a browser tab. The ideal size for a favicon is 32x32 or 256x256 pixels. You can use our Figma plugin to put your designs in the right size.
  • Open Graph Image : When you share a blog post or page on social media, an image is often displayed. The ideal size for an Open Graph image is 1200x630 pixels

Formats adapted for the web

The image format you choose can also affect the loading speed of your site. The format WEBP, for example, offers better quality compression than JPEG or PNG. If you're using Webflow for your site, there are ways to convert your images to WEBP. Discover how to compress your images in Webp in Webflow

In conclusion

Properly sizing, optimizing and adjusting the weight of your images for the web is not only a question of aesthetics. This is a crucial step to ensure good site performance, better accessibility and optimal SEO. By using best practices and the right tools, you can ensure that your images are perfectly suited to the modern web.