Vivaldi vs Midori

Since Vivaldi is built on Chromium, the same base as Chrome (among other browsers) is built on, it was possible for Vivaldi developers to allow Chrome extensions to run in their browser.

Tabs can be grouped under a single tab to easily keep track of all open webpages.

Vivaldi has a lot of features and customizability. Far more then most (perhaps all) other browses, and many to list them all individuality as separate pros.

A feature called Quick Commands (accessed via Ctrl + Q) allows quickly getting to settings, history, open tabs, bookmarks with incremental search.

Web Panels allow for easy access to any site from the side panel. They are useful for reading two websites side by side or for chatting (i.e. Facebook) and surfing at the same time. Panels can be hidden when not in use.

Vivaldi is available on Windows, GNU/Linux and macOS, so it covers the most used PC operating systems.

It's possible to change and add keyboard shortcuts for basically all commands. It also has single key shortcuts to execute actions with one click.

You can add as many search engines as you like. For example you can set up one for YouTube, one for Wikipedia, or whatever you want: you need only the URL of the search and it can be used from the URL bar (by prefixing it's nickname, yt for YouTube for example).

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.

A notes panel allows to save notes from webpages and can include screenshots for reference and have tags and organized in folders to help manage them. Thumbnails are too small and Notes do not have separate page in settings, but it should, there are a lot of things to improve.

Everything can be synced with a Vivaldi account. Though there's still no mobile version, you can sync between computers and OSes.

The order you toggle, open, close or clone tabs can be modified to match a workflow that best works for you. For example you can choose tabs to toggle in recent order so you can go back and forth between the last most useful tabs without needing to change their position on the tab bar.

Vivaldi can grab a picture of the whole webpage or part of it and saves it automatically inside a note or as a file in your disk, or in your elected directory. But I have problems with images of full windows shown on monitor (using X Window System in GNU/Linux). Here I use system XWindow screenshots.

View graphically your most visited pages on a monthly, weekly, or daily basis.

A setting lets you prevent closing fixed tabs so you don't close anything important by accident.

You can change tab bar position to top, bottom left or right.

For you programmers out there: Since Vivaldi uses JavaScript, React, Node.js, Browserify and multiple npm packages to build the browser, it can be customized with ease by anyone who knows HTML, CSS, and JavaScript.

It saves oversights many options and functions implemented in Vivaldi. E.g. see CON "No option to open saved tab stack as... tab stack!"

Vivaldi has a built-in reader mode so you can remove all the clutter in news pages and read only the content, you can also customise the reader mode, like font size, style and colours.

There's even an option to automatically transition from light to dark based on the time of day.

In comparison, on Chrome you will not see the address bar, only on ChromeOS when your mouse is on the top of the screen.

Vivaldi has an excellent bookmarks system. Bookmarks can be easily accessible via Speed Dial, side-bar, bookmarks bar, quick commands. No more messy bookmarks bar is needed and location bar suggestion is improved thus!

It is so faster and safer.

A feature called "fast forward" puts a dedicated button before the address bar. It takes you to the next page of a multi-page article, forum thread, or search results, without having to hunt for the link.

A built-in setting called "Broadcast IP" will stop the IP leaking with WebRTC when disabled.

Vivaldi has a built-in blocker that allows you to select between blocking just trackers or both trackers and ads. With customizable blocking list sources, good performance, and support for all the standard blocker list features you find in ad blocker extensions (with more to come), you might not need an ad blocker extension at all.
This also comes in handy on Android, where Chromium/Vivaldi doesn't support extensions.

Respects Privacy.

Unlike most modern browsers (but like most browsers of yesteryear), Vivaldi gives you a dialog box when an new version comes out; it doesn't just update silently in the background. The dialog box tells you about the changes that have been made, and lets you chose when you want to update.

Most portable version cannot be added as default apps but Vivaldi offers that option and it comes with updater too.

Just bookmark a page and you can henceforth open it by a shortname of your choosing.

Relieve your eyes or save space on the screen – your choice!

The optional feature for controling various functions (e.g. opening, closing and switching of tabs) by pressing just a single key rather than two turns out to be an extremely convenient extra.

Vivaldi can change the colors across the browser and has the option to change the color automatically depending on the page. Also, page loading animations are available in the address bar.

Unlike most modern browsers (but like most browsers of yesteryear), Vivaldi has a status bar. But the status bar is optional, you can turn it off (in the settings) if you don't want it. Vivaldi also has a side-panel, which again, can be turned off.

Midori is considerably fast. It starts up in no time and renders pages as fast as many other more well-known browsers.

Incredibly lightweight with very little memory consumption.

Midori has a built-in functionality with which you can create web apps that can be launched from the desktop. For example, you can create a web app for the desktop to launch Gmail or YouTube or any other web app that you use.

Midori is used as a default choice for a web browser for some distributions (like Elementary OS) and it's available for easy downloading for many other distros through their official repositories.

Some very popular and useful plugins are built-in and available out of the box. For example, there's an RSS feed reader plugin and an Adblocker built-in.