Exit polls show the center-right Christian Democratic Union party leading, with the AfD party heading towards the strongest showing of the far-right since World War II.

Germany's conservatives won the national election on Sunday, while the far-right Alternative for Germany came in second, its best ever result.

Centre-right opposition leader Friedrich Merz’s conservative bloc emerged as the frontrunner in Germany’s national election on Sunday, though without a decisive victory, according to exit polls by ARD and ZDF public television.

Germany’s centre-right CDU and CSU parties have won the federal elections with about 28.5 to 29 per cent of the vote according to exit polls, paving the way for CDU leader Friedrich Merz to become chancellor at a time of economic and political upheaval in Europe’s largest democracy.

Polls are open across Germany as the world’s third largest economy chooses a new leader to guide it through an era of febrile immigration debates and souring relations with Washington.

While polling suggests Germany's far-right AfD party will fare well, it's very unlikely to be part of the next government of Europe's biggest economy.