When comparing Mozilla Firefox vs FOSS Browser, the Slant community recommends Mozilla Firefox for most people. In the question“What are the best Android web browsers?” Mozilla Firefox is ranked 5th while FOSS Browser is ranked 20th. The most important reason people chose Mozilla Firefox is:
Firefox [scores strongly on HTML5 feature support](http://html5test.com/results/desktop.html). Though not as strongly as Chromium/Chrome browsers do.
Specs
Ranked in these QuestionsQuestion Ranking
Pros
Pro Strong HTML5 feature support
Firefox scores strongly on HTML5 feature support.
Though not as strongly as Chromium/Chrome browsers do.
Pro Syncs between devices
Firefox Sync is an optional feature in Firefox that allows syncing bookmarks, passwords, and add-ons between devices.
Pro Free, open source and community driven
Firefox is available as a free download. All Mozilla software is licensed under the Mozilla Public License. Instructions on how to obtain the source code can be found here.
Pro Respects your privacy
Mozilla is one of the first browsers that advocates privacy. They believe that internet should be in the user's control and not those who run the websites, and so they give tools inside the browser to make the user be more in control.
Pro Strong developer tool
The built-in developer tools have been merged with the popular FireBug extension since FF57.
Pro High performance
The Firefox Quantum update (FF57) greatly increases the render speed and general performance of the browser, by taking better advantage of the user's hardware.
Pro Reader View
Reader View in Firefox allows users to read an article without any distractions by removing ads, unrelated elements and other distractive objects (similar to Microsoft Edge's Reading Mode and Safari's reader mode).
Pro One of the few browsers not using Chrome's Blink engine
Firefox uses its own rendering engine (called Gecko), instead of Google-controlled Blink like the vast majority of other browsers.
Pro Fast
With new integrations focused on security and performance, Firefox is faster and less likely to have problems during use than ever before.
Pro Open Source
Open Source means that you can see the source code. So everybody even if they don't work for Mozilla is able to look what the browser does in the background. So you can be 100% sure that Firefox doesn't have hidden "spy features" unlike Google Chrome.
Pro Good font rasterizing
Font rasterizing on Windows is much better than in competitors. Even smaller text is clear and contrast.
Pro Automatically updated
Firefox is automatically updated on the platforms where it makes sense.
Pro Uses less resources
Firefox 57 (Quantum) and newer uses less resources than ever. It is proven with benchmark done by AppleInsider.
Pro Dark theme
Beyond the toolbar and tabs, it darkens UI elements such as the URL-bar, pop-downs, new-tab page and more.
Pro Awesome customizability
Great library of add-ons.
Pro Tagging bookmarks
Firefox is one of the few browsers that you can tag your bookmarks. You can view a list of tags and can search your bookmarks in the address bar with tags.
Pro Really independent browser
It's not dependent on Google.
Pro Screenshot tool
Powerful screenshot tool built right into the browser.
Pro Ethical and pragmatic company mission
The Mozilla Manifesto outlines the company's mission and principles. Paraphrasing, they want the Internet to be a free and open resource, and to enable individuals to get the best use of that resource. They do this by creating open source software to which anyone may contribute, so long as such contributions fit with their principles (both ethical and technical).
Pro A lot of add-ons
An enormous number of add-ons.
Pro Fast bookmark management
In order to add an open page to the bookmark bar, the tab can be dragged down and is added immediately.
Pro Built-in privacy protection
Blocks tracking cookies, finger print scanners and Cryptominers by default. Can be changed to the user's individual needs.
Pro Lower memory fingerprint than competitors
Firefox used to be a trailer in memory usage, but as of 2017 it's less hungry for memory than competitors like Edge, Chrome, Safari and Opera.
Pro Text-to-speech (with adjustable speed) without add-ons
Firefox Reader Mode includes Narrate, a feature that adds text-to-speech functionality to the browser.
Pro Very secure
Pro Firefox experiments
FF experiments are Mozilla projects available from FF Test Pilot, such as Firefox Colour, witch lets you customise your browser theme to your liking!
Pro Firefox Lockwise password management
Helps store your usernames and passwords. Lockwise also lets you know if any of the sites you have login details for have had their (and potentially your) data leaked!
Pro HTML5 video preload
The only web browser that only preloads entire HTML5 video which is useful for slow internet.
Pro Mobile
Firefox has a solid mobile app.
Pro Integration with Pocket
Firefox comes with built-in Pocket integration that can allow users to quickly save the article for a read it later function to easily find any articles saved in Pocket from various sources and devices.
Pro Installed by default on many Linux distributions
Many Linux distributions come preinstalled with Mozilla Firefox
Pro About:config
Master about:config and uBlock Origin, and all Firefox-based browsers will be yours.
Pro WebRender
The newer versions of it will soon use WebRender to render webpages, which'll make it much more efficient by utilizing GPU to paint webpages.
Pro UI
UI is better than any other chromium-based browser.
Pro FOSS
The name itself suggest FOSS (Free Open Source Software).
Pro Respects your privacy better than all other Chromium based browsers
Requires more flexibility if possible.
Pro No trackers
Recent version of app.
Pro Excellent flexible app user data management
Complete user's custom browser settings, database (site settings such as whitelisting, etc.) and bookmarks can be exported (as a backup) and then imported (to be restored for later use).
Important Note:
Before uninstalling and reinstalling the browser app, create an archive or a copy of the already backed-up data of it to another location of data storage.
Pro UI/Handling
Optimized for one hand handling (toolbar at bottom).
Pro Multi tab browsing
Tab control (switch, open, close unlimited tabs) mentioned by developer, supported (limit to device available memory).
Pro Websearch (from marked text context menu)
Pro Search on site
Pro Advanced gesture control for toolbar and navigation button
Pro Fast toggle for most important settings
Pro Navigation button in fullscreen mode
Pro Do not track me
Mentioned by developer.
Pro Delete data on exit (optional)
Mentioned by developer.
Pro Toggle image/third party content loading
Mentioned by developer.
Pro Whitelist from setting
Whitelist for javascript, cookies and adblocker.
Pro Third party cookies disabled by default
Mentioned by developer.
Pro Custom user agent switcher
Supported & adaptive (most flexible).
Pro Save web page as PDF (URL to PDF)
Supported (but check complexity of web page).
Pro App optimization
Installation size under 10 to 20 MB (depends upon OEM manufacturer & data usage by user).
Pro Adblock filters
Supported.
Pro Excellent Bookmarks Management
Import & Export Bookmarks, very few browsers have this rare functionality.
Cons
Con Some built-in advertising
With their new "pocket" feature, they offer advertisements built-in.
Con Cannot directly translate page
Unlike Google Chrome, if you visit a website with a different language, you cannot translate it, which is a bad user experience for some.
Con Lack of keyboard shortcuts customization
Keyboard shortcuts can not be changed in a user-friendly way.
It is also difficult to manipulate addons with hotkeys.
Con When you search in a website (Ctrl + F) there are no marks appearing in the right scrollbar
All Chromium based browsers have this feature.
Con Installs Addons with updates
Mozilla is installing/integrating addons with every update like the Mr. Robot promotion - it also has integrated Pocket that spams you every time you open the browser or a new tab with partners of Pocket.
Con Uses Google as its default search engine
Which is pretty ironic for a browser that's focused on "privacy".
Con Sometimes very buggy and slow
On sites like twitch.tv chat scrolling is still not fixed. Compared to other browsers Firefox is still very slow and feels sluggish.
Con Uses GTK on Linux/BSD
This makes the integration on non-GTK Desktop Environments very hard.
Con Multi Profile is not user friendly
Multi profile requires commandline -no remote to use and open about:profiles to create manually (on Chrome, you can instantly create them on right top user button).
Con Antivirus has False positives
All Downloads in Firefox are scanned for viruses, but there are a lot of false positives.
Con Doesn’t support multiple languages for spell check
If you write in multiple languages, you need to manually switch the spell check language.
Con Terrible user interface
Con Crappy license
Cannot redistribute binary after source code modification.
Con Major updates may break any installed add-ons
Con Now forces install and use of snap
Only on Ubuntu
Con New icon looks ugly
Con GTK Themes styles the HTML forms
If you're in Linux and you use a dark GTK theme that uses white text and come to a webpage that forces black text on html-forms buttons you will get black buttons with unreadable black text.
Con Doesn't care for its original guidelines/goals
Mozilla originally aimed to be the "good guys" with user choice and privacy in mind. Their current leadership cannot be trusted to hold those goals in high regard:
1) Added Pocket - a privacy data sensitive plugin, made it mandatory
2) Tried to sneak in advertisement as "drive-by hack", backpedaled unconvincingly once users complained
3) Tried to randomly inject a small percentage of Firefox downloads in Germany with a data collecting plugin (Cliqz) that tech-savy Germans consider adware (no opt-out question asked).
Con It's a memory hog even though Mozilla claims it is not
Mozilla claims it's using 30% less RAM than Chrome but in real life tests it uses much more.
Con Android permission location
Today, most browser developers put 2 location permissions: 1) Precise & 2) Approximate, most people search goods & services "by typing name of specific region or place".
i.e: books library in "name of city"
So, is there any need to such permissions which is a privacy concern ?
Con Github users may track you
Con Backed by Github.com
Github is known for making it open source, and hosting tech pros, open source user, and others. This was made to be better then Chrome.