Soon from Opera 12.50 release onwards you can not install extensions from third-party sites as easily as you’re used to now, Opera intentionally blocking these add-ons to prevent any chances of malware installing on to users Computers, two months back we’ve covered that Opera software planning to block third-party extension installations then version name from which they implement was not announced, today Opera confirmed in their desktop team blog that change reflects from today’s Opera 12.50 snapshot onwards. So if you now try to install add-on away from Opera add-ons site in Opera 12.50 you’ll likely to get a warning “for your safety, you can only install extensions from”.

Its not Opera browser first to do this, Chrome already implemented this without any blog post or announcement, we’ve covered how to install third-party extensions in Chrome where you need to drag and drop downloaded extension onto extensions page to install.

installation blocked

That’s not possible in case of Opera where you need to add site from which you’re going to install to Trusted repositories. This is not that difficult, but if you’ve to test different add-ons hosted on different sites then you need to whitelist all those sites by adding them to Trusted websites list which can be tedious.

Installing Third-party extensions in Opera 12.50

If you trust the source site, then you can add it to Opera trusted repositories by

1. Press Ctrl +F12 to open Preferences

2.  Click on Advanced tab, select Security >Trusted Websites

3. On Trusted Websites window, use add button to enter the website address in the field from which you want to install add-on

Opera Trusted websites

4. Click on Close button, restart the browser now try to install the extension from the website you added just now, extension will be downloaded and installed without any warnings.

downloading extension

We’ve tested the above method and successfully installed WOT add-on for Opera hosted on mywot.

By default Opera comes with addition of following sites as trusted, the below sites allow users to install extensions from Opera add-ons catalog and also updates installed extensions. 

There is no chance that other sites appearing in this list without your permission unless you added them in the past.