SeaMonkey vs Opera : Which is Better?

SeaMonkey

SeaMonkey is a free and open-source Internet suite. Developed by The SeaMonkey Council

License: Open Source

Apps available for Mac OS X Windows Linux BSD PortableApps.com

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

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