When comparing Lightning vs Firefox Focus, the Slant community recommends Firefox Focus for most people. In the question“What are the best Android web browsers?” Firefox Focus is ranked 13th while Lightning is ranked 17th. The most important reason people chose Firefox Focus is:
It automatically blocks any ad trackers and erases your browsing history which includes your passwords and cookies.
Ranked in these QuestionsQuestion Ranking
Pros
Pro Free and open source software
This means you can help developing new features if you would like to contribute.
Moreover you can inspect the code if you are concerned about privacy.

Pro Built-in reading mode
Reading mode allows removing everything on a page but the content. It removes ads, styling and anything else that could get in the way of a comfortable reading experience.

Pro Slide-out tab switcher
Tab switcher can be quickly accessed by swiping from the left.

Pro Incognito mode
Pro Keeps your activities private
It automatically blocks any ad trackers and erases your browsing history which includes your passwords and cookies.
Pro Good loading speed
Since it blocks ads, trackers and other things that can slow down web pages, you'll be able to browse the web faster.
Pro Simple to use
Pro Suitable as a secondary browser for everyday use
As it is very fast and private it can be used for everyday use together with a browser with your passwords and login information.
Cons
Con No bookmark folders
Bookmarks can't be organized into folders.
Con Notification spam
Tells you to clean the browser every single time you open it.
