Similar to popular browser extensions like AdBlock Plus, the new Opera feature will prevent any adverts appearing on webpages, even getting rid of the ads which run before YouTube videos.
However, since the feature is a native application and not an add-on, Opera claims it's on average 45 per cent faster than Google Chrome with the AdBlock Plus extension.
Writing on the browser's website, senior vice-president of engineering and new products Krystian Kolondra said: "Today, bloated online ads use more download bandwidth than ever, causing webpages to load more slowly... another rising concern is privacy and tracking of your online behaviour."
Kolondra said the feature was created in order to improve users' experiences, and to send a message to advertisers.
The ad-blocker is deactivated by default, but when a page with adverts is loaded, a pop-up will appear asking: "Would you like to block ads and surf the web faster?"
If blocking is turned on, users will be able to see how much load-time they've saved. They can also add certain sites to an exception list, allowing adverts to run if they want to support them.
Opera is a fairly small browser, used by around two per cent of the world's internet users, compared to Google Chrome's 59 per cent.
If their native ad-blocker is adopted by bigger browsers in a similar way, it could mean trouble for free websites which rely on advertising to make money.
The feature is now available in the latest version of the developer browser. If the test is successful, it'll make it to the regular version.