When comparing Chromium vs Epiphany, the Slant community recommends Chromium for most people. In the question“What are the best desktop web browsers?” Chromium is ranked 4th while Epiphany is ranked 43rd. The most important reason people chose Chromium is:
Unlike Google Chrome, Chromium is completely open source.
Specs
Question Ranking
Pros
Pro Completely open source
Unlike Google Chrome, Chromium is completely open source.
Pro Supports all of Google Chrome features
As Chrome is based on Chromium they overlap in supported features. Chromium syncs between devices, automatically updates, has great built-in developer tools, installs extensions without a restart, includes a combined text bar for entering URLs and searching and has excellent HTML5 compatibility just like Chrome.
Pro Access to Chrome's extensions
Chromium can access the Chrome Web Store and all the extensions hosted there can be installed and used on Chromium.
Pro Cross-platform
Chrome and Chromium are available on almost every device nowadays
Pro Sandboxing
Every tab and plugin runs in its own subprocess so they will never affect the whole browser ,however that consumes more memory than other browsers
Pro Backed by Google
Chromium was first released as a large portion of Chrome's source code as an open source project by Google in september 2008. The idea was to encourage developers to review the underlying code and to contribute in making Chrome cross platform and port it to Mac and Linux as well.
Nowadays Chromium is a large project with a huge community that's standing behind it but still Google continues to take an extremely active role in Chromium development. This ensures the longevity and constant development and improvement of the browser.
Pro Lightweight
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 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).
Pro GNOME integrated
Includes features specific to GNOME like turning sites into apps that are managed with GNOME software and the ability to install GNOME extensions.
Pro For Linux and Windows
Available for Linux and Windows 10 with WSL, see here.
Cons
Con High RAM usage
Just like Chrome, Chromium also eats a lot of RAM, which can be a problem for machines with smaller RAM.
Con Lacks privacy options
Con Misses some proprietary multimedia codecs
Unlike chrome, Chromium misses proprietary multimedia codecs per default. There might be some ways over ffmpeg and co but it is still a gray zone. Also by enabling, it also removes one of the core features of Chromium of being open source software
Con Lacks support for certain common media formats
As Chromium avoids bundling any proprietary software, media that requires proprietary codecs or formats such as AAC, H.264, MP3 and Flash will not play by default on Chromium.
Con No official builds
There are no official builds available so you have to rely on a third party distributor
Con Not possible to disable WebRTC
Con Can be dangerous
There are plenty of Chromium distributors and every one of them can disable specific features (like sandboxing) for their build, so you will never know what you get.
Con Simple, dull, bare-boned
Con Doesn't read cookies properly
... and for this reason it only remembers the user logins only in the session. Once the browser is restarted for whatever reason, it forgets everything and the user has to login again everywhere which can become annoying very quickly.
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.
Con Crashes often
Epiphany can crash on a heavy load or when closing/opening tabs. While this only happens every few days, it still happens more often than in most other browsers.
Con Becomes messy on highly graphical pages
Sometimes struggles to handle complex graphical pages such as Facebook. In these circumstances, it becomes 'messy' - text and graphics get mixed up - and will eventually crash. Even so, this is a light and useful browser.