Posts

Showing posts from November, 2011

Using HTML5's Navigation Timing API to measure Page Load speed

Image
To measure the time taken for a page to load one can use the Date object in the head section and calculate the time taken for the page to load in window.onload function. However, it calculates the time taken for the page to load after the first bit of JavaScript in the head is executed. This doesn't indicate the time taken by the web server to serve the requested page. The Navigation Timing API introduced in HTML5 provides data that can be used to measure the performance of a website. The API provides a PerformanceTiming interface which contains several attributes that can be used to get end-to-end latency data.

Using HTML5's PageVisibility API

Today I stumbled upon the PageVisibility API introduced in HTML5, which gives developers an opportunity to improve the performance of a web page and to better the user experience. Whenever a user opens a new tab or navigates to another tab, the behavior of the current page from which user navigated can be controlled using this API. Consider a webmail client that is trying to look for new mails every two seconds, if a user opens a new tab or minimizes the browser window then retrieving mails every two seconds would expend resources, whilst the user is not actively viewing the page. Here the PageVisibilty API would come handy and would allow developers to alter the behavior of the web page.