Image weight

What is image weight ?

The weight of an image, just like any other file, corresponds to the size it occupies in bytes on a hard disk. It also corresponds to the amount of data to be exchanged with the WEB server, in order to be retrieved by the browser to display it on a page.

Images can be saved in different formats and can be optimized using compression algorithms, with or without loss of quality.

The most common formats are :

  • JPEG / BMP: for photographs and printing
  • PNG : for qualitative images needing transparency
  • GIF: for small animated images that require transparency and/or a low color set

Why is this important ?

The weight of images can quickly become problematic, it generally takes up a significant place in the overall weight of resources to be loaded on a page. Images can therefore seriously slow down the complete loading of a page and its global rendering by the browser. Compressing an image can drastically reduce its weight, so it is essential to optimize it since the user will not see any difference in its quality.

How to optimize them ?

Optimizing images means adapting their format and quality for the WEB, it is useful to :

  • choose the most suitable format
  • convert them to the new Google WebP format using a utility such as online-convert, which allows you to convert images in different formats online
  • compress them with a utility such as imagecompressor which allows to compress JPEG / PNG images.
  • Find more information on Google's Image Optimization Guide