Only the pre-defined search engines that come with Opera can be set as the default one.

@leocg Evidently I broke a rule - sorry about that. I will read the instructions and repost appropriately. Thank you for your patience.

@nebulousecho this has been requested for quite some time now... either one can add ecosia as search engine or (what i do), i just use this opera addon which allows me to set whichever website i want as default when opening a new tab. I know it's not ideal, but currently there's not many other options.

Google doesn't separate search results that much anymore - like they used to do for different language areas. Sure China still get's the treatment. If Opera continues to be the only browser with forced default engine ~ step 1 would add option to choose a country code (ccTLD) from a short list including .com!

@m-n-g I think it is only work in address bar not in Speed Dial bar. So, type in address bar Edit : Sorry, I didn't read this forum is for Linux. I use Windows 10 v.1709 (RS3)

@silas229 Except, maybe, for Edge/IE and Chrome, almost all browsers get their revenues from searches and from pre-added bookmarks/speed dials.