Germans are voting on Sunday in a nationwide election to elect a new parliament and determine who will succeed Angela Merkel as chancellor.
Christian Democrats' Armin Laschet and Social Democrats' Olaf Scholz are frontrunners in the race, while the Greens' candidate, Annalena Baerbock, is third in the latest surveys.
Days before the polls, nearly 35% of voters were still undecided about who they would vote for or if they would vote at all, making predictions difficult ahead of the historic vote.
Merkel is still the country's most popular politician but she is not running for another term and will step down after the formation of a new government.
Polling stations opened at 8 a.m. (0600GMT) at nearly 85,000 locations across the country and will close at 6 p.m. (1600GMT).
Germany's Federal Election Commissioner asked people to observe anti-coronavirus measures at polling places -- wearing a mask in the building, complying with hygiene and social distancing measures.
Many Germans have already cast ballots by mail, largely due to coronavirus concerns, and authorities expect more than 40% of votes to be mail-in ballots in this election.
Nearly 60.4 million people are eligible to vote in the election, including 2.9 million first-time voters, according to authorities.
The first exit polls will be published shortly after polling stations close and preliminary results are also expected later on Sunday.
The latest survey on Friday by the Allensbach Institute suggests a head-to-head race between conservative leader Laschet and social democrat candidate Scholz.
The institute predicted that Scholz's Social Democratic Party (SPD) would win 26% of the vote. Laschet's conservative CDU/CSU alliance was expected to get 25%. Baerbock's environmentalist Greens was polled at 16%.
The same survey showed support for liberal Free Democrats (FDP) at 10.5%, with the far-right Alternative for Germany (AfD) just behind at 10%, followed by the anti-capitalist Left Party at 5%.
Surveys have indicated that none of the parties will get enough votes to govern alone, and the winning party's chancellor candidate will likely face tough negotiations to form a coalition government.
Germany's chancellor is elected indirectly, with voters choosing new parliament members, who then determine the new chancellor with a vote among themselves.
If the wining party secures a majority in parliament, or manages to build a coalition government with an absolute majority, its candidate becomes the country's next chancellor.
In Sunday's parliamentary election, more than 6,200 candidates from 47 political parties are contesting to obtain a seat in parliament, also known as the Bundestag.
Six parties and party alliances are expected to pass the %5 threshold and enter the Bundestag.