Opera Software has updated its desktop browser to block ads without the need for a plug-in.

With its 2.07 percent share of the desktop browser market last month, according to StatCounter, Opera’s move is unlikely to scare advertisers, or website operators dependent on advertising revenue — particularly as the blocker is turned off by default.

However, the browser might interest website operators, as with a single click it allows them to compare the load times of their sites with ads, and without, and gain some understanding of what their revenue generation may be costing them in lost visitors.

Some top websites load up to 90 percent faster without ads, according to Opera senior vice president for engineering Krystian Kolondra.

Put another way, that means adding ads to those sites makes them take ten times longer to load.

That’s a big problem for publishers and advertisers, as 40 percent of visitors abandon websites that take more than three seconds to load, according to research by KissMetrics in 2011.

While ad-blocking technology is already available for the major desktop browsers in the form of plug-ins or add-ons, Opera has incorporated it right into the core of the application.

The blocker is turned off by default, but the browser will prompt users to enable it when it detects ads it could have blocked.