When comparing Mozilla Firefox vs Epiphany, the Slant community recommends Mozilla Firefox for most people. In the question“What are the best desktop web browsers?” Mozilla Firefox is ranked 1st while Epiphany is ranked 34th. The most important reason people chose Mozilla Firefox is:
Firefox [scores strongly on HTML5 feature support](http://html5test.com/results/desktop.html).
Ranked in these QuestionsQuestion Ranking
Pro Strong HTML5 feature support
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 Syncs between devices
Firefox Sync is an optional feature in Firefox that allows syncing bookmarks, passwords, and add-ons between devices.
Pro Strong developer tool
The built-in developer tools have been merged with the popular FireBug extension since FF57
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 Awesome customizability
Pro Automatically updated
Firefox is automatically updated on the platforms where it makes sense.
Pro Good font rasterizing
Font rasterizing on Windows is much better than in competitors. Even smaller text is clear and contrast.
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 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 Uses less resources
Firefox 57 (Quantum) and newer uses less resources than ever. It is proven with benchmark done by AppleInsider.
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 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 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 Easy screenshots without extensions
Within the browser itself, you can easily take screenshots and save them to your computer.
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 Android version allows installation of addons
Epiphany is pretty lightweight and doesn't require much memory to start up.
Pro Fits in perfectly with the GNOME desktop
Since it is a GNOME app, you get all the benefits of the GNOME desktop. It's easy to use, Epiphany just works out of the box. It stores your web site passwords in the secure GNOME keyring, and uses your existing desktop settings to launch applications and access the network, so you don't need to configure everything twice.
Pro Excellent alternative to the most popular web browsers
Sometimes my workflow involves using separate browsers. I like mail in app tabs, but some jobs are well suited to a lighter, simpler web browser.
Pro For Linux and Windows
Available for Linux and Windows 10 with WSL, see here.
Pro Default in many GNOME versions
Epiphany has been the default browsers for many distributions that use stock GNOME for a long time now (although it's being replaced by the much more popular Firefox lately).
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: https://www.cnet.com/news/mozilla-backpedals-after-mr-robot-firefox-misstep/
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) : https://bugzilla.mozilla.org/show_bug.cgi?id=1406647
Con Uses GTK on Linux/BSD
This makes the integration on non-GTK Desktop Environments very hard.
Con Sometimes stop working for few seconds
Sometimes stop working for 10/15 seconds, then starts working again. Inconvenient when looking streaming video on youtube or twitch
Con Styles HTML-forms with the OS/Desktop theme
At least on X11/Unix that leads to terrible issues, that makes some websites simply unusable for example: If 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 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 Gets slower with every extension
Until the 10th extension it works fine but after that it suddenly becomes slower and slower and at some point it takes forever to start - if it starts at all.
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 Poor performance on SSD even without extensions
On a fast SSD such as Corsair Force LE series this browser still performs as if it were installed on a regular hard drive disk, meaning it takes long time to start, even without any extensions. On that matter Google Chrome is light years ahead of Firefox. This applies only for Firefox versions below 60!
Con It's bloated
Just remember that Firefox was created to create a simple and fast browser that would focus on web browsing. However, nowadays Mozilla is adding more and more extensions like pocket or screenshots to the browser(that could easily be done as optional add-ons) that will bloat it just like the old Mozilla Suite (nowadays Seamonkey).
Con Not much room for configuration
The choice for extensions is very limited, although there are decent extensions for the most useful activities and features it still cannot compare to the extensive collections that other browsers may have access to.
The number of tweaks that can be done to the browser from the options menu is also very limited since Epiphany follows a philosophy of "less is more". While this can be enjoyable for some it still hinders a lot of functionality and removes the ability to personalize the browser the way you want it to be.