Google Compression Proxy Statistics

Google has published statistics ( pdf ) on the operation of the Data Compression Proxy service for the mobile web (by the way, there is an extension that allows traffic from the Chrome desktop browser to be passed through this proxy, but few use it).

This is an analogue of the famous Opera Turbo service, which also compresses text content and compresses pictures more strongly.

The service, code-named Flywheel focuses specifically on the mobile web, and it comes by default with Chrome and iOS browsers. The desktop extension does not come with a browser, because it is the mobile web that has recently begun to generate the bulk of the traffic on the Web, while most sites are still optimized for desktops, and mobile traffic is relatively expensive.

According to a published document, a proxy from Google compresses traffic by an average of 58% and is based on the SPDY transport protocol and WebP format. This is a big advantage, because support for these formats with a high degree of compression is still implemented on a scanty number of sites: 0.8% of images on the Internet in WebP and 0.9% of sites support SPDY.

The greatest compression benefit comes from WebP, which reduces image size by an average of 66.4%. It turns out that it is WebP that contributes 85% to the overall savings, and the benefits of SPDY and other things are not so significant.



Only 9% of mobile Chrome users turned off the data compression feature by default. At the same time, it is automatically turned off on HTTPS sites and on tabs in incognito mode (it’s silly to forward traffic through Google servers in this mode).

General traffic statistics are interesting in the sense that many users use incognito mode and other proxy bypass methods, including audio / video files in this category (13% of traffic), and how popular are HTTPS (50% of traffic). Everything else goes through Flywheel.

About 78% of all page downloads on the mobile web are via WiFi, 11% by 3G, 9% by 4G / LTE and 1% by 2G.

Despite the high compression, the actual page loading speed does not increase much: only 6%, on average. This is because requests go through the Google servers. A more significant increase in speed was noted for really large pages and for users close to Google data centers.

The report notes that Opera Turbo has similar statistics.