Picto thématique

Rule n° 219 - The server transmits compressed contents to the clients which accept them.

This is a particularly effective way of speeding up page access time and reducing bandwidth costs: a server can be configured to send compressed pages (in a format similar to that of a .zip archive). The contents are then "unzipped" on the fly and in a totally transparent manner on the user's workstation.

#Eco-conception #Server and performance #Development


  • Improve the speed of the page’s rendering.
  • Reduce bandwidth costs.
  • Reduce the energy impact related to the consultation of the site.


Activate the server's Gzip or Deflate module to compress JavaScript, CSS and HTML resources.


For each page checked:

  • Check the content compression (Gzip) using a dedicated tool.

Be careful to check all of the linked elements (CSS, JS, HTML) and not just the page itself. Formats such as JPEG or PNG images or zip files which are already compressed, for example, should not be recompressed. If

the size before compression of an element is less than 1 kB, it is not necessary to compress it, because the size might increase.

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Business application and benefits

The rules should be applied to your projects from the design phase through to post-implementation , and they should be understood by all professionals with web and customer experience (CX) responsibilities: from strategy to operations, marketers to project managers, and editorial to technical staff. The benefits of using this ruleset are numerous, including improving customer satisfaction, web performance, and e-commerce, and expanding your client base, while also decreasing your errors and costs.

Multidisciplinary verticles - accessiiblity, SEO, e-commerce, ecodesign etc..- starting from the foundational Opquast base.

The objective of these rules and the Opquast community mission is ‘making the web better’ for your customers and for everyone! Opquast rules cover the key major areas of risk that can negatively affect website users such as privacy, ecodesign, accessibility and security.

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