WhatsApp Web doesn’t work in Vivaldi

The issue is essentially the same as for Chromium explained in WhatsApp Web is asking to update Chrome while using Chromium. Vivaldi isn’t supported by WhatsApp Web officially, so it used spoofing in the past, but a recent update broke that and the feature is not implemented again yet. There are three ways to work around the issue:

Temporarily change the tab’s User Agent

Pro: fast and simple, Con: needs to be done again after every reload of the tab

In the WhatsApp Web tab:

1. right-click and select “Inspect”
2. click the vertical dots button on the top right
3. click “More tools” → “Network conditions”
4. on the bottom at “User Agent”, uncheck “Select automatically”
5. from the dropdown list directly below choose “Chrome — Windows”
6. reload the tab by clicking the ↻ button, pressing Ctrl+R or right-clicking inside it and selecting “Reload”

If that doesn’t work, clear the site’s locally stored data: Right-click and select “Inspect” if you don’t have the window still open, go to the “Application” tab on the top, select “Clear storage” on the left and click the “Clear site data” button, then reload the tab again.

Persistently change the tab’s User Agent with an extension

Pro: persistent, Con: needs an extension

You can use an extension like User-Agent Switcher for Chrome to set a persistent User Agent for individual tabs, this is explained in detail in this answer.

Persistently change the whole browser’s User Agent by altering its start command

Pro: persistent, Con: changes the User Agent for every other tab as well

Vivaldi has a --user-agent command-line option which you can use to easily set the browser’s User Agent. For WhatsApp Web it’s enough to cut “Vivaldi/x.x.xxxx.xx” from the current User Agent line:

1. Visit vivaldi://about and copy your current User Agent without the “Vivaldi/x.x.xxxx.xx” at the end

2. Close the browser and start it again using this shortened User Agent line, e.g.:

   vivaldi-stable --user-agent='Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/74.0.3729.134 Safari/537.36'
   

If you want to tweak a .desktop file, just replace its

Exec=/usr/bin/vivaldi-stable %U

line with e.g.:

Exec=/usr/bin/vivaldi-stable --user-agent='Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/74.0.3729.134 Safari/537.36' %U

Sources and Further reading

• WhatsApp Web is asking to update Chrome while using Chromium
• Blog article “WhatsApp Web doesn’t support Vivaldi browser, here is how you can make it work in Vivaldi again”