Ranked in these QuestionsQuestion Ranking
Pro Tab can be stacked
Tabs can be grouped under a single tab to easily keep track of all open webpages.
Pro Built on web technology
Pro Built for power users
Vivaldi includes lots of niche functionality such as the ability to move tabs to any side of the screen, turn images on and off, or render pages with monospace fonts.
Pro Compatible with most Chrome extensions
Since Vivaldi is built on WebKit, the same engine Chrome (among other browsers) is built on, it was possible for Vivaldi developers to allow Chrome extensions to run in their browser.
Pro Can be completely keyboard-driven
All actions required to interact with the browser like navigating webpages and changing settings can be performed using only keyboard, no mouse required.
Vivaldi is available on Windows, Linux and OSX.
Pro Ability to search through settings, history, open tabs, bookmarks in one place
A feature called Quick Commands (accessed via Ctrl + Q) allows quickly getting to settings, history, open tabs, bookmarks with incremental search.
Pro Mouse gestures
Integrated mouse gestures. Fully configurable as of Vivaldi 1.2 (snapshot available now). Allows for navigating the web, switching tabs, closing windows, opening settings etc. with a flick of the mouse.
Pro Add websites as web panels for easy access
Allows for easy access to any site and for reading two websites side by side. Useful for chatting (i.e. Facebook) and surfing at the same time. Panels can be hidden when not in use.
A notes panel allows leaving notes on webpages and can include screenshots for reference and have tags and organized in folders to help manage them.
Pro Allows navigating to the next page without searching for the link
A feature called fast forward puts a dedicated button before the address bar that is designed to help you navigate to the next page of a multi-page article, forum thread or search results without having to hunt for the link.
Con New and buggy
Still working out a few kinks, not entirely optimized yet so it can be a little slow or resource intensive.
Con Developer Tools does not embed
While Vivaldi is currently available gratis (without monetary charge), it is currently not libre (meaning that it does not allow users to view the source code used to create, to modify that code, or to redistribute modifications) and is therefor e neither free nor open-source software.