While Google's dominance of desktop search in Europe remains unshakable, it's a different story in the US: Firefox users have helped push Yahoo's search share to a five-year high, apparently at Google's expense.

According to web stats firm StatCounter, Google's share of the US search market in December was its lowest since 2008, dipping to 75.2 percent from 77.3 percent in November. At the same time, Yahoo's share climbed to 10.6 percent from 8.6 percent, while Bing remained nearly flat, inching up to 12.5 percent from 12.1 percent.

The analytics firm made no claim to the cause of Google's dip, but noted that the shift coincided with Mozilla's deal with Yahoo in November, which came into effect in December and saw Yahoo replace Google as the default search option in the Firefox mobile and desktop browser in the US.

Aodhan Cullen, CEO of StatCounter, said Mozilla's move to Yahoo "had a definite impact on US search". It remains to be seen, he added, whether Firefox users will switch back to Google in future. Current versions of Firefox allow users to choose their preferred search provider from a number of companies including Bing, Google, DuckDuckGo, and Yahoo.

Figures from ComScore last October - ahead of Mozilla's switch to Yahoo - pegged Google's share of the US search market at 67 percent, with Microsoft at 19.4 percent, and Yahoo at 10 percent.

According to StatCounter, Firefox users accounted for just over 12 percent of US internet usage in December.

The analytics company reported in December that the release of Firefox 34, the first with Yahoo as the default search provider, pushed Yahoo usage in the browser to 30 percent, up from 9.6 percent in Firefox 33.

While the change in desktop search is significant, a bigger issue for Google could be its mobile presence, where it holds just under 90 percent of the US market . According to a report in The Information late last year, Microsoft and Yahoo are both gunning to replace Google as the default search provider for Safari on iOS.

Read more on this story

