This guide explains how to enable DNS over HTTPS (DoH) in the Opera browser and route requests through your personal ADnull DNS.
Step 1. Open Opera Settings
Click the O logo in the top left corner → Settings, or open a new tab and go to:
opera://settings
Step 2. Go to Advanced settings
Click Advanced in the left menu → Privacy & security.
Step 3. Find Use secure DNS
Find the Use secure DNS option → enable the toggle → select Specify (or Other provider).
Step 4. Enter the DoH address
Paste the address into the field:
https://YOUR-SUBDOMAIN.dns.adnull.com/dns-query
Replace YOUR-SUBDOMAIN with your personal subdomain — it is shown in the Settings section of your ADnull account.
Click Save.
Done!
Opera now uses ADnull DNS. Ads and trackers are blocked at the DNS level in your browser.
FAQ
Where do I find my subdomain?
Go to the Settings section in your ADnull account — the subdomain is shown in the "DNS Domain" card.
DoH was not applied after saving
Restart Opera. Also make sure Opera's built-in VPN is disabled — it can conflict with DoH settings.
Does Opera's built-in VPN affect DoH?
Yes. If Opera's built-in VPN is enabled, DoH may not work correctly.
Disable Opera VPN in settings and test DoH again.