Researchers find ways to cut the energy that smartphones need to access sites

Smartphone users know that watching a video or playing a game can quickly drain a battery. Free apps are also power-hungry, and even simple Web browsing has an energy cost.

Now, researchers at Stanford University and Deutsche Telekom have discovered that such popular sites as Wikipedia, IMDB and even the home page of Apple are wasting energy due to bloated code. The researchers have also shown how to reduce this energy usage by almost 30 percent without affecting user experience.

Stanford computer scientist Narendran Thiagarajan and colleagues used an Android phone hooked up to a meter to measure the energy used in downloading and rendering 25 popular Web sites. Simply loading the mobile version of Wikipedia over a 3G connection consumed just over 1 percent of the phone’s battery, while browsing to Apple.com, which does not have a mobile version, used 1.4 percent.

The team then repeated the measurements with locally saved versions of the Web site; doing so allowed them to separate out the energy required to render a page from that needed to download it. The researchers discovered that many of the Web sites they looked at were loading large files that weren’t being used in the page being viewed.

By rewriting the code for one Wikipedia page to perform only the required function, Thiagarajan’s team reduced the energy used from 15 to 9.5 joules, which would help battery life. They say that Web designers should consider the energy used in loading a page, thereby helping smartphone users and others preserve their battery life.

— New Scientist