Module 1: Checkpoint 14—Online files must be optimised

Conformance: Desirable

Requirements

All web resources and assets should be optimised for performance. This includes images, stylesheets, scripts, PDF, and PowerPoint.

Benefits of conformance

  • Optimisation of assets ensures smaller file sizes and fewer HTTP requests for faster downloading of pages.
  • Responsive web experience for all users, including those with low bandwidth fixed or mobile internet access.

Risks of non-conformance

  • Increased download times due to larger file sizes.
  • Possible migration to other, more expensive channels due to slow response times.

Implementation advice

Explanation

There are many ways to optimise web resources for online delivery; some key areas of focus are:

  • keeping markup as lean as possible
  • reducing the number of HTTP requests required for each page by combining asset files where possible
  • reducing asset size by minifying and/or compressing file contents
  • ensuring assets are cacheable by optimising server configuration
  • sharing central assets to reduce redundant downloads of identical assets.

The supporting information for this checkpoint provides more information about how to optimise for online delivery.