Opera vs Firefox Developer Edition : Which is Better?

Opera

Opera is a one of the major web browsers with good extension functionalities. Developed by Opera Software

License: Free

Apps available for Mac OS X Windows Linux Windows Mobile Android

Firefox Developer Edition is a special edition of Firefox for developers. Developed by Mozilla Foundation

License: Open Source

Apps available for Mac OS X Windows Linux PortableApps.com

Feature	Opera	Firefox Developer Edition
Based on Blink engine
Built-in Ad-blocker
Built-in Download Manager
Built-in VPN
Based on Chromium
Extensible by Plugins/Extensions
Multiple languages
Resume interrupted downloads
Tabbed browsing
Block ads
Auto-login
Bookmarks
Built-In Proxy
Built-in RSS reader
Web Browsers Based on Chromium
Customizable
Explorer-like
Flexible customizations
Support for gestures
Group tabs
Limit cpu usage
Limit ram usage
Mouse gestures
Night mode/Dark Theme
Opera-like
Pop out video
Portable
Privacy Protected
Real-Time Synchronization
Session management
Sidebar
Spatial navigation
Support for Chrome extensions
Sync between devices
Tab preview
Tabbed interface
Text Wrapping
UI customization
WebRTC
Whatsapp integration
Privacy focused
Support for TOR
Security & Privacy
Cloud sync
Tab Stacking
Android Sync
Built-in Adobe Flash Player
Extensions
Chrome-like
Support for 64 bit
Privacy enhanced
Web Browsers Based on Firefox
Lightweight
Customizability
Developer Tools
Web Development
Integrated into iOS
Content blocker
Sync with iCloud
Firefox Extensions
Auto Updates
Block trackers
Bookmark organization
Based on Firefox