Incumbent President Joko Widodo has appealed to voters to unite and put national solidarity foremost, while calling on his supporters to keep a low profile, following bitter elections that saw quarrels among families and friends, and the spread of hoaxes.
He acknowledged the exit poll and quick-count results that showed he was leading, but quickly appealed to supporters to wait for the official vote-counting by the General Elections Commission (KPU) next week, at the soonest.
Mr Joko is seeking a second five-year term in office, squaring off against his sole rival, former army general Prabowo Subianto.
In 2014, Mr Prabowo lost to Mr Joko, who garnered a majority vote.
"From the indications of exit polls and quick counts, we saw everything, but we should be patient and wait for the official count from the KPU," Mr Joko said.
Quick counts by Jakarta-based Poltracking Indonesia gave Mr Joko - popularly known as Jokowi - the winning margin, with a 55.19 per cent vote share over Mr Prabowo's 44.81 per cent, while the Indikator showed the smallest victory margin of 53.92 per cent to 46.08 per cent.
The counts are based on more than 90 per cent of the ballot data targeted for sampling by pollsters.
Quick counts have consistently shown accurate results since 2004, the first time Indonesia held its first direct presidential election.
Mr Joko later posted on Facebook: "My fellow citizens and countrymen. Alhamdulillah (All Praise to God), today Indonesia has held the 2019 General Election peacefully and safely. Thank you to everyone who has used their voting rights the best they can.
"This year's democracy party provides a lot of experience, learning, as well as challenges for us as a nation. Whatever the outcome, let's maintain and care for our unity and brotherhood as a large and diverse nation," he wrote.
Mr Ali Nurdin, a political analyst at Mathla'ul Anwar University, said that Mr Joko's decision to refrain from claiming victory based on the quick-count tallies was different from his reaction after the last election five years ago, when he embraced the projections.
"Last time, he wasn't an incumbent. It was normal that he was more assertive then. His position now is a symbol of a country, head of state. He has to show political maturity," said Mr Ali.
"As the leader of Indonesia, once again, Jokowi has an uphill task going forward," he said, adding that the President has to lead in the effort to reunite Indonesians cleaved by political differences. "This is why he has to be wise so as not to worsen such divisions," Mr Ali added.
At around 8pm, about 200 supporters of Mr Joko gathered outside one of their main campaign centres in Jakarta, celebrating the election's quick-count results.
Supporters hoisted party flags, danced and sang songs, while a person pointed a water hose at the centre of the crowd.
When the campaign for the presidential election peaked and pushed divisive issues to the fore, observers and experts suggested changes to make the electoral system fairer and less polarising.
With the seven-month-long election campaign, many voters have fallen into two opposing camps, fanatical about who they support. Some have lost the ability to soundly discuss issues.
Mr Prabowo's camp has been blamed for playing identity politics and the religion card. Both camps have blamed the other for spreading hoaxes that have caused rifts within families and communities.
Political experts, such as Professor Komaruddin Hidayat, rector of state-run Syarif Hidayatullah Islamic university, feel that Indonesia should relook how the polls are run. He suggested a system where voters elect their MPs who, in turn, pick the president and vice-president. He said this would focus voter attention on a party or a coalition's policies and plans, rather than on the few personalities on the election ticket.