Just came across this article from early 2017
One of those out of mind out of site topics
I'd expect the firefox options might be out of date
Websites and web pages are constantly growing in size and today it’s not unusual for the average page to be a few Megabyte in size. There are even websites around with single pages in the tens of Megabytes. While this might not be a major issue for people with a fast or unlimited internet, there’s still a huge proportion of people that don’t have a reasonable speed internet connection.
If you include people using mobile broadband dongles or metered internet connections it becomes a major issue and a drain on bandwidth when pages are not properly optimized.
Optimizing a web page can be as simple as compressing images and using HTML code and scripts that have no unnecessary code. The page will load faster for everybody especially for those on slower connections because less data needs to be downloaded.
Bandwidth Saving Web Browser Extensions
1. Google Data Saver Beta (Chrome)(in example saves 26.6%)
4/5 star rating(3688 votes) - not for https sites
Anonym zu https://chrome.google.com/webstore/detail/data-saver/pfmgfdlgomnbgkofeojodiodmgpgmkac/reviews?hl=en
2. SkyZIP (Chrome and Firefox)
4 1/2/5 stars (968 votes)
Andreas BuxbaumDec 1, 2017
Hi, the traffic on our servers is heavy because of some abuse users. We will release a newer much better version soon. With some more features and even more through put.
Anonym zu https://chrome.google.com/webstore/detail/skyzip-proxy/hbgknjagaclofapkgkeapamhmglnbphi?hl=en
3. Network Bandwidth Saver (Firefox)
4. Data Compression Proxy (Chrome) - no longer offered
Web Browsers With Built In Bandwidth Saving
1. Opera Browser
Opera is very well known in this field and has had page compression in Opera and Opera Mini for a long time, it was one of the first to enable the bandwidth saving compression feature in mobile browsers. They also have an Android app called Opera Max that offers media compression across other apps on your device.
2. UCBrowser
UCBrowser is a very popular and well known mobile browser with hundreds of millions of downloads to its name. UCWeb also have a PC version of their browser based on Chromium
3. Yandex Browser
Yandex Browser is based on Chromium and integrates a feature that enables page compression, which is a modified version of Opera’s own Turbo mode
Final Note: As you might expect mileage with this type of function will vary greatly from site to site and it depends mostly on how well the site you visit has been optimized that will decide how much bandwidth saving there will be.
For example, Raymond.cc has a number of optimizations to serve pages as quickly as possible to all users, so a bandwidth saver would not produce much saving.
Other sites will get big savings because they aren’t well optimized, somewhere like TMZ.com can be compressed by over 50% saving several Megabytes on a single web page.
Expanded picture reviews , direct links which are tested with virus total before linking you
& a few user comments
Anonym zu https://www.raymond.cc/blog/fastun-saves-mobile-internet-bandwidth-usage/