Chromium Blog: Reload, reloaded: faster and leaner page reloads

Chromium Blog

News and developments from the open source browser project

Reload, reloaded: faster and leaner page reloads

Thursday, January 26, 2017

Reload has long been a staple feature of web browsers and kept its original behavior throughout the years, despite the changing landscape of web platform innovations, connectivity, and content consumption patterns. When reloading a page, browsers will check with the web server if cached resources are still usable, a process known as validation. This typically results in hundreds of network requests per page issued to dozens of domains. On mobile devices, the high latency and transient nature of mobile connections mean that this behavior can produce serious performance issues. In the latest version of Chrome, changes to page reload behavior produce reloads that are 28% faster and result in 60% fewer validation requests.

Users typically reload either because a page is broken or the content seems stale. The existing reload behavior usually solves broken pages, but stale content is inefficiently addressed by a regular reload, especially on mobile. This feature was originally designed in times when broken pages were quite common, so it was reasonable to address both use cases at once. However, this original concern has now become far less relevant as the quality of web pages has increased. To improve the stale content use case, Chrome now has a simplified reload behavior to only validate the main resource and continue with a regular page load. This new behavior maximizes the reuse of cached resources and results in lower latency, power consumption, and data usage.

Despite being a relatively minor change, the new behavior makes reloads up to 28% faster and consume less bandwidth and power. Furthermore, Facebook contacted us with data showing that Chrome was sending validation requests at three times the rate of other browsers. Thanks to the new reload behavior and some related changes, Facebook now reports 28% faster page reloads and 60% less validation requests from Chrome.

We hope this faster reload will come in handy whenever you want to get the latest content on your favorite website or quickly recover from a flaky connection in the subway.

Posted by Takashi Toyoshima, “Reloader Sensei”