Although an internet connection has become quite affordable in the past few years, the mobile data plans are still very steeply priced. For only a few measly gigabytes of data, the mobile data service providers can charge you a hefty sum of money. And these gigabytes, usually advertised so profusely by the cell service providers, actually consist of both the uploaded and downloaded data combined together. So if you pay $80 for 10 GB of data, then you may not be able to download 10 GB as some of the bytes are always used in uploading something. To make economic use of mobile data plans on your PC, you can use the Google Data Compression for the Chrome browser which can save your costly internet bandwidth by as much as 80%.
The Data Compression extension for the Chrome browser is actually the PC version of the Data Saver feature already present in the Android version of Chrome browser. A similar feature called the Off Road mode is also offered by the Opera browser. The Google Data Compression extension redirects your non-secure (HTTP) traffic through the proxy servers which are configured to compress the data before it arrives on your PC. For the secure connections (HTTPS) it does not redirect the web traffic.
After the installation of the Data Compression extension in your Chrome browser, you can click on its icon in the Chrome omnibar to see how much data has been saved by the extension. You can also toggle on or off this extension from here. There are no options to be configured for the Google Data Compression extension.
Verdict: Although the Data Compression (or Data Saver) extension for Chrome can reduce the internet bandwidth usage by a great amount, some of the privacy conscious users may be concerned as all the HTTP traffic is routed through Google servers. If you are worried about this, then you can toggle the extension off when visiting sites in question.