Vivaldi is not open source,

but you can read its source.

published: 05/31/17

last updated: 06/12/18

I'll be honest: I actually wrote this on Reddit, but it's something I'd like to be able to reference easily in the future because this topic comes up relatively frequently when someone mentions Vivaldi, so I'm putting it on my website as well.

You can't build Vivaldi yourself from source because Vivaldi isn't open source. Part of it is, specifically, the changes the Vivaldi devs make to Chromium are open source under a BSD license. But the frontend, that's to say, the ui, is not open source. But you can still read and edit the ui's source, you just can't repackage the changes you make and distribute it. That's not to say you can't share your modifications, but I'll talk more about that in a bit.

Vivaldi's interface is written in human readable web languages which are easy to learn. Specifically, it's coded in html, css, and javascript. So the source is readily available and easily accessible in the user's install directory as .html, .css, and .js files. If you're on Linux, the installation directory is /opt/vivaldi/resources/vivaldi/ or /opt/vivaldi-snapshot/resources/vivaldi/ depending on which release cycle you're using.

So as long as you know where it's located on your system, and so long as you know css and javascript, there's nothing at all stopping you from reading, analyzing, or modifying the source code to your liking. It's not only possible, but the devs encourage and enable it! I mean, there's even a subforum for user modifications on the official Vivaldi forums, right here. And just to drive it home, here's a tutorial written by a Vivaldi staff member on where to find Vivaldi's files and how to edit them.

Here are some popular examples of existing user mods:

You can even contribute to the project, as in this post where a user made changes to Vivaldi that improved performance and submitted them to Vivaldi staff, who then merged it. I don't know of any other specific examples, but according to this Vivaldi dev on Reddit, other users have submitted changes to him that he ended up merging.

So, again, no, Vivaldi is not open source, but only in a strictly legal sense. You can easily access and read Vivaldi's source, so it's easy to confirm that Vivaldi Technologies isn't doing anything obviously shady with users' data. Which means, really, that the only reasons someone would care about Vivaldi's license is ideological, or brand loyalty to the company that made their preferred browser, and not out of concern for their privacy or security.

And just one last thought, I would certainly prefer if Vivaldi were open source, but I'm not a free software activist, I'm a user. And as a user, it's more practical for me to use Vivaldi for its features than to settle for an inferior product simply because it is open source.

See also: