1.3.4 Client and server side processing

Initial data validation (JavaScript) Manipulates user interface elements Applies website styles (CSS) Reduces load on the server Reduces the amount of web traffic

Provides further validation Queries and updates the server database Encodes data into readable HTML Keeps organisation data secure Performs complex calculations

Web traffic is reduced and so less bandwidth is used. Reduces the load on the server as it does not have to do the processing. Helps ensure that data sent to the server passes validation rules. Interactive widgets, such as a pop-up calendar assists the visitor to enter data correctly. No delays in processing local data.

The browser must support Javascript (most do) Javascript has to be enabled in order to run (some users and admins turn it off). Page loading is slower as the Javascript script has to be loaded by the browser. Search engines will find it difficult to index a JavaScript-heavy page, as much of the content is created as the page loads. It needs technical skills to write JavaScript code from scratch, although there are plenty of JavaScript libraries such as JQuery available that reduce this burden.

Faster load time Easy indexation by search engines Fewer issues with social media indexing Better in terms of accessibility

Increase in expenses May cause slower page rendering Problems with compatibility HTML with a larger size