Vivaldi is not open source,

but you can read its source.

published 05/31/2017

updated 06/05/2017

updated 01/20/18

I'll be honest, I wrote this on Reddit before posting it here. 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 the source. Vivaldi is not 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 is not open source and is under a more restrictive license. Even so, you can see the UI's source and even edit it. Just open the installation directory. Vivaldi's files are human readable and written in web languages, which are easy to learn. The installation directory on Linux is /opt/vivaldi/resources/vivaldi/ or /opt/vivaldi-snapshot/resources/vivaldi/ depending on which release cycle you're using. But you don't have to extract anything, it's all readily available in .css, .js, and .html files.

Here is Jon von Tetzchner, Vivaldi's CEO, on the subject.

As long as you know where it's located on your system, and as long as you know CSS and Javascript, there's nothing stopping you from reading and modifying the source as you see fit. Not only is it possible, but there's a subforum on the official Vivaldi forums for user modifications, and people are making modifications all the time. For some examples, see:

The Vivaldi devs not only support the community in their endeavors to modify Vivaldi, but a member of the Vivaldi staff wrote a short tutorial about where to find Vivaldi's files and how to modify them. You may not be able to fork Vivaldi or to redistribute its files, but modifying it and sharing those modifications are entirely possible and allowed. It also doesn't mean it's impossible to officially contribute to Vivaldi!

Here's an example: a user made changes to Vivaldi that improved performance, he submitted the changes to Vivaldi staff, they merged it. I don't have any other examples, but according to this Vivaldi dev on Reddit, other users have submitted changes to him that he ended up merging.

Ultimately Vivaldi is not open source, but because the source is so easy to access and read, it's easy to confirm that Vivaldi Technologies is not doing anything shady with users' data. Which means that the only reason someone would care about Vivaldi's license for ideological reasons, as opposed to any real security or privacy concerns. I would certainly prefer if Vivaldi were actually open source, but I'm not a free software activist, I'm a user.

See also:

#onlycss changelog