Edge is the latest release of browser from Microsoft, whereas Firefox was long in the business of Internet Browser.
With almost millions of user worldwide, Firefox managed to get great fame whereas Edge browser (previously know as Internet Explorer) was defamed due to bad performance and some lacking issue.
Performance
You must know that 70% of Mozilla Firefox users are from countries where speed of internet is very good such as US, Hongkong, etc. you will find almost everyone using it. It is a net hungry program but besides it, you will get everything out from the webpage. Every picture will be loaded with high quality and everything will be perfect.
Microsoft Edge browser was targeted to slow internet and fast internet as well. You will not feel lack of performance while using it on a Windows machine. Either you have a slow internet or a faster one you will definitely love performance of it.
Design
Firefox regularly comes with improved design. Recently, They launched a new version of Firefox in the favor of Windows 10 which will feature a windows based look. You should definitely check it out.
Edge browser is made to work on Windows and comes with completely same design as it. You will feel like you are using another Windows app while using it.
Extension
Mozilla Firefox comes with a vast range of Extension whereas there is no extension support in Edge Browser. You will definitely feel lack of it which will make you mind to go for Google Chrome or Mozilla Firefox.
Best for Developers
If you are a Web Developers then Mozilla Firefox will stand up to your needs. It is said to be the best Internet browser in the market for developers. You can easily download few extension and can churn out your need from the browser.
Edge browser is pretty much basic browser. It lacks in Developers support. Microsoft should pay serious attention towards this matter.
Final Verdict
Mozilla Firefox is far better than Edge browser but if you live in a place where you get slow internet speed then Edge Browser will be better for you.
I am currently pursuing High School and planning to pursue career in Computer. Currently, I work on one of my blog - JTech Articles.