When comparing Mozilla Firefox vs Vivaldi, the Slant community recommends Mozilla Firefox for most people. In the question“What are the best desktop web browsers?” Mozilla Firefox is ranked 5th while Vivaldi is ranked 9th. The most important reason people chose Mozilla Firefox is:
Firefox [scores strongly on HTML5 feature support](http://html5test.com/results/desktop.html) Though not as strongly as Chromium/Chrome browsers do.
Ranked in these QuestionsQuestion Ranking
Pro Strong HTML5 feature support
Firefox scores strongly on HTML5 feature support
Though not as strongly as Chromium/Chrome browsers do.
Pro Free, open source and community driven
Firefox is available as a free download. All Mozilla software is licensed under the Mozilla Public License. Instructions on how to obtain the source code can be found here.
Pro Syncs between devices
Firefox Sync is an optional feature in Firefox that allows syncing bookmarks, passwords, and add-ons between devices.
Pro Strong developer tool
The built-in developer tools have been merged with the popular FireBug extension since FF57.
Pro High performance
The Firefox Quantum update (FF57) greatly increases the render speed and general performance of the browser, by taking better advantage of the user's hardware.
Pro Respects your privacy
Mozilla is one of the first browsers that advocates privacy. They believe that internet should be in the user's control and not those who run the websites, and so they give tools inside the browser to make the user be more in control.
Pro Reader View
Reader View in Firefox allows users to read an article without any distractions by removing ads, unrelated elements and other distractive objects (similar to Microsoft Edge's Reading Mode and Safari's reader mode).
Pro Uses less resources
Firefox 57 (Quantum) and newer uses less resources than ever. It is proven with benchmark done by AppleInsider.
Pro Awesome customizability
Great library of add-ons.
Pro Tagging bookmarks
Firefox is one of the few browsers that you can tag your bookmarks. You can view a list of tags and can search your bookmarks in the address bar with tags.
Pro Android version allows installation of addons
Unlike other browsers, Mozilla uses almost the same codebase as with the desktop version so extensions work as-is without code modifications - something other browsers cannot do due to their breaking and sometimes unrelated code branches to the mainline desktop branch.
Pro Automatically updated
Firefox is automatically updated on the platforms where it makes sense.
Pro Dark theme
Beyond the toolbar and tabs, it darkens UI elements such as the URL-bar, pop-downs, new-tab page and more.
With new integrations focused on security and performance, Firefox is faster and less likely to have problems during use than ever before.
Pro Good font rasterizing
Font rasterizing on Windows is much better than in competitors. Even smaller text is clear and contrast.
Pro Ethical and pragmatic company mission
The Mozilla Manifesto outlines the company's mission and principles. Paraphrasing, they want the Internet to be a free and open resource, and to enable individuals to get the best use of that resource. They do this by creating open source software to which anyone may contribute, so long as such contributions fit with their principles (both ethical and technical).
Pro Fast bookmark management
In order to add an open page to the bookmark bar, the tab can be dragged down and is added immediately.
Pro Open Source
Open Source means that you can see the source code. So everybody even if they don't work for Mozilla is able to look what the browser does in the background. So you can be 100% sure that Firefox doesn't have hidden "spy features" unlike Google Chrome.
Pro Screenshots tool
Powerful screenshots tool built right into the browser.
Pro One of the few browsers not using Chrome's Blink engine
Firefox uses its own rendering engine (called Gecko), instead of Google-controlled Blink like the vast majority of other browsers.
Pro Lower memory fingerprint than competitors
Firefox used to be a trailer in memory usage, but as of 2017 it's less hungry for memory than competitors like Edge, Chrome, Safari and Opera.
Pro A lot of add-ons
An enormous number of add-ons.
Pro Text-to-speech (with adjustable speed) without add-ons
Firefox Reader Mode includes Narrate, a feature that adds text-to-speech functionality to the browser.
Pro Really independent browser
It is really independent browser, unlike many other that are based on Chromium.
Pro Firefox Experiments
FF Experiments are Mozilla projects available from FF Test Pilot, such as Firefox Colour, witch lets you customise your browser theme to your liking!
Pro Built-in Privacy Protection
Blocks tracking cookies, finger print scanners and Cryptominers by default. Can be changed to the user's individual needs.
Pro Firefox Lockwise Password Management
Helps store your usernames and passwords. Lockwise also lets you know if any of the sites you have login details for have had their (and potentially your) data leaked!
Pro Easy screenshots without extensions
Within the browser itself, you can easily take screenshots and save them to your computer.
The newer versions of it will soon use WebRender to render webpages, which'll make it much more efficient by utilizing GPU to paint webpages.
Pro Integration with Pocket
Firefox comes with built-in Pocket integration that can allow users to quickly save the article for a read it later function to easily find any articles saved in Pocket from various sources and devices.
Pro HTML5 Video Preload
The only web browser that only preloads entire HTML5 video which is useful for slow internet.
Pro Compatible with most Chrome extensions
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.
Pro Tabs can be stacked
Tabs can be grouped under a single tab to easily keep track of all open webpages.
Pro Lots of features and customizability
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.
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 Full of customizable keyboard shortcuts (can be completely keyboard-driven)
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.
Pro PC Cross-platform
Vivaldi is available on Windows, GNU/Linux and macOS, so it covers the most used PC operating systems.
Pro Web Panels
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.
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 Programmable user interface
Pro Built-in page capture
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.
Pro Tab behaviour can be customised
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.
Everything can be synced with a Vivaldi account. Though there's still no mobile version, you can sync between computers and OSes.
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.
Pro Reader mode
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.
Pro Analytical history
View graphically your most visited pages on a monthly, weekly, or daily basis.
Pro Non-closable fixed tabs
A setting lets you prevent closing fixed tabs so you don't close anything important by accident.
Pro Custom search engines
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).
Pro Cross browser extensions with Opera and Chrome, Firefox web-ext's too
All Vivaldi, Opera and Chrome users can get extensions from all extension/addon sites, especially from Opera Addons and Chrome Store.
Pro Tab bar position can be changed
You can change tab bar position to top, bottom left or right.
Pro Manages bookmarks well
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!
Pro Dark theme out of the box
There's even an option to automatically transition from light to dark based on the time of day.
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. It takes you to the next page of a multi-page article, forum thread, or search results, without having to hunt for the link.
Pro WebRTC IP leaking can be disabled
A built-in setting called "Broadcast IP" will stop the IP leaking with WebRTC when disabled.
Pro Saving sessions
It saves oversights many options and functions implemented in Vivaldi. E.g. see CON "No option to open saved tab stack as... tab stack!"
Pro Usable fullscreen mode with address bar when needed
In comparison, on Chrome you will not see the address bar, only on ChromeOS when your mouse is on the top of the screen.
Pro Updates via dialog box
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.
Pro Portable version can be added on default apps
Most portable version cannot be added as default apps but Vivaldi offers that option and it comes with updater too.
Pro Fast and safe
It is so faster and safer.
Pro Customizable UI
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.
Pro Side panel and status 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.
Con Some built-in advertising
With their new "pocket" feature, they offer advertisements built-in.
Con GTK Themes styles the HTML forms
If you're in Linux and you use a dark GTK theme that uses white text and come to a webpage that forces black text on html-forms buttons you will get black buttons with unreadable black text.
Con When you search in a website (Ctrl + F) there are no marks appearing in the right scrollbar
All Chromium based browsers have this feature.
Con Cannot directly translate page
Unlike Google Chrome, if you visit a website with a different language, you cannot translate it, which is a bad user experience for some.
Con Installs Addons with updates
Mozilla is installing/integrating addons with every update like the Mr. Robot promotion - it also has integrated Pocket that spams you every time you open the browser or a new tab with partners of Pocket.
Con Uses GTK on Linux/BSD
This makes the integration on non-GTK Desktop Environments very hard.
Con Lack of keyboard shortcuts customization
Keyboard shortcuts can not be changed in a user-friendly way.
It is also difficult to manipulate addons with hotkeys.
Con Sometimes very buggy and slow
On sites like twitch.tv chat scrolling is still not fixed. Compared to other browsers Firefox is still very slow and feels sluggish.
Con Uses Google as its default search engine
Which is pretty ironic for a browser that's focused on "privacy".
Con Partial dark mode
Bookmark, context menu, etc. are not themed.
Con Crappy license
Cannot redistribute binary after source code modification.
Con Mozilla once partnered with George Soros to fight misinformation
Mozilla once partnered with George Soros to fight misinformation.
Con Devtools for WebExtensions are buggy
Con Multi Profile are not user friendly
Multi profile require commandline -no remote to use and open about:profiles to create manually (on Chrome, you can instantly create them on right top user button).
Con Promotes a political agenda
Promotes a political agenda in your browsing experience via Messages and Pocket recommendations
Con Abandoned XUL for WebExtensions
Con It's Mozilla
Con Terrible user interface
And you can't even fix it anymore because they removed XUL
Con Doesn’t support multiple languages for spell check
If you write in multiple languages, you need to manually switch the spell check language.
Con False positives in virus-scanner
All Downloads in Firefox are scanned for viruses, but there are a lot of false positives.
Con Doesn't care for its original guidelines/goals
Mozilla originally aimed to be the "good guys" with user choice and privacy in mind. Their current leadership cannot be trusted to hold those goals in high regard:
1) Added Pocket - a privacy data sensitive plugin, made it mandatory
2) Tried to sneak in advertisement as "drive-by hack", backpedaled unconvincingly once users complained
3) Tried to randomly inject a small percentage of Firefox downloads in Germany with a data collecting plugin (Cliqz) that tech-savy Germans consider adware (no opt-out question asked).
Con It's a memory hog even though Mozilla claims it is not
Mozilla claims it's using 30% less RAM than Chrome but in real life tests it uses much more.
They run experiments with users as a form of data collection.
Con Sometimes buggy
Con Not available on the iPhone
There is an Android version Vivaldi, but no iOS version. iPhone and iPad users are out of luck.
Con Same security-holes as Chrome
Vivaldi uses the same browser engine as Chrome, meaning it has the same security-holes as Chrome. Chrome is a big target for hackers (being the most popular browser in the world), and a webpage that will hack Chrome may also hack Vivaldi.
Con Can't disable all spyware features
Con Advertisements in the bookmarks
By default: Vivaldi has a number of websites (such as Amazon) already bookmarked. New bookmarks may be added to the speed-dial when the browser updates. These bookmarks can be deleted, same as any other bookmark, but that will not stop new bookmarks form being added.
Con Freezes often
Con Can't protect pinned tabs from changing to another URL
Clicking on a page link, then another, easy to wind up far from the original pinned tab site. There is no chrome addon or native vivaldi function to stop this.
Con No guarantee that you won't lose your session
The browser window may freeze at any time, and you lose all your progress, open windows, and session without an option to restore it next time you open your browser.
Con No automatic page translation
Unlike Chrome, it doesn't automatically translate pages that are not in your language.
Con Extensions miss hotkeys
You can set your shortcuts at vivaldi://extensions, but they do not work.
Con Developers do not care for your privacy
Con Still dependent on Google
Con Feature creep
Con No silent background updates
Unlike most modern browsers, Vivaldi doesn't have the option to update silently in the background. It gives you a dialog box when an update comes out. Worse, the box doesn't warn you that not updating the browser could lead to security risks. That could be pretty bad for your average joe, who doesn't know computers that well.
Con No option to open saved tab stack as a tab stack
You may save stack, but you can open it as separate tabs. Interesting that when you save session with stacks, you'll be able to open the stacks with inner settings of page tiling (size and zoom) as well. Contradiction worth of shame.
Con No touch bar support
While Vivaldi is currently available gratis (without monetary charge), it is currently not fully 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 therefore neither free nor open-source software.
The C++ source code however is open-source under a BSD license and can be downloaded and browsed from here.
The UI code though is not open-source, but it's easily readable as it's HTML, CSS & JS. Modifications can be shared as their forum even has a dedicated section.
Con No built-in proxy
Unlike Opera (but like most browsers), Vivaldi doesn't have a proxy service out of the box. You'll need an extension or an external program, to use Vivaldi with a proxy server.