Save-Data: on от Aleksandersen

Tell websites that you prefer to save data and costs. At websites’ discretion, you may see lower quality images and fewer media elements as webpages adjust to reduce data downloads.

The extension works by sending the Save-Data: on HTTP header with every request. This extension is not a data compression proxy like the Data Saver option in Google Chrome, or Opera Turbo and Yandex.browser Turbo mode.