Opera 65 Beta released on October 17 supports DNS-over-HTTPS (DoH) protocol, which feature helps to encrypt DNS traffic, and increase users' privacy and security by protecting against eavesdropping and manipulation of DNS data through man-in-the-middle attacks.
While Cybersecurity Experts have vehemently opposed the DNS-over-HTTPS protocol because actually, DoH doesn't prevent ISPs from tracking its user, and it renders enterprise cyber-security set ups weak, as it overwrites the centrally-imposed DNS settings to allow employees to use DoH to bypass any DNS-based traffic filtering solutions.
And the fact that DNS traffic is centralized to a few DoH resolvers, there's the problem of DoH's impact on the DNS ecosystem itself, with the decentralized network of servers giving way to new layer of DoH resolvers, which sits on top of the existing DNS layer.
Opera also decided to default the DNS resolver to Cloudflare for the test, which path was equally followed by Mozilla, the Firefox browser maker, having Cloudflare to power the DNS over HTTPS functionality of the Firefox browser, which was received with lots of criticism, as most security researchers believed the idea of domiciling all the DNS traffic to Cloudflare, is a bad idea.
Google took a different route in implementing DNS over HTTPS on Chrome browser, by allowing the availability of several DNS providers in the test, instead of domiciling all DNS traffic to Cloudflare.
The DNS queries on Opera browser will go through Cloudflare servers, and for requests that cannot be handled by Cloudflare, will have to go through the local DNS server by allowing the browser to connect to local resources.
Albeit, the Opera DNS-over-HTTPS feature is not enabled by default, the user will have to enable it by navigating to opera://flags/#opera-doh in the web browser's address bar. Then the right experimental flag will be loaded on the internal opera://flags page directly.
But you can also load opera://flags and directly search for Secure DNS to set the Secure DNS (DNS over HTTPS) flag to Enabled. And you'll have to restart the Opera web browser for it to take effect.
Opera Software, however did not prioritize privacy in the documentations, rather the company has only entered into a deal with Cloudflare to limit data exposure, usage and retention when a user enables the service.