Outgoing President Joko Widodo has presided over steady growth and relative stability in the past decade in the mineral-rich Group of 20 economy of 270 million people, establishing it as a future base for multinationals in the electric vehicle supply chain.
Still, Widodo, who is widely known as Jokowi, has in the run-up to Wednesday's presidential election faced criticism over his perceived political meddling and push to establish a political dynasty.
Prabowo Subianto (centre) is leading in the polls over Ganjar Pranowo and Anies Baswedan. (AP PHOTO)
He has not explicitly endorsed any of the three presidential candidates but has made highly publicised appearances with controversial former special forces commander Prabowo Subianto, and his eldest son is running on the same ticket for vice-president.
Two opinion surveys last week projected Defence Minister Prabowo, who is making his third run to be president, could secure more than 50 per cent of the votes on Wednesday, allowing him to win in a single round.
Rivals Anies Baswedan and Ganjar Pranowo were seen at least 27 and 31 points behind him respectively.
Indonesia has entered a cooling-off period until voting day, with candidates barred from campaigning.
Running the world's largest single-day election is a gargantuan task.
The archipelago of more than 17,000 islands stretches across three times zones and a distance similar to across the United States.
Election officials have delivered ballot boxes and papers to far-flung regions, in some cases travelling hours by boat, helicopter or ox-drawn carts.
Outgoing President Joko Widodo has faced criticism over his perceived political meddling. (AP PHOTO)
The weather agency has warned about the risk of extreme weather in West Java on polling day, media reported.
Meanwhile, the election commission has postponed voting in 10 villages in the Karanganyar district in Central Java due to flooding.
Jokowi's tacit backing of Prabowo has led to accusations he has flouted election rules, which he rejects.
In Indonesia, sitting presidents can campaign for candidates providing they do not use state resources and must take official leave to do so. Incumbents have typically been neutral.
The presidential office has denied political meddling by Jokowi.
Hundreds of students held noisy street protests on Monday to protest against what they see as democratic backsliding under Jokowi, a former furniture salesman who seemed to offer a clean break from the military and political elite.
In 1998, huge student protests fuelled unrest that led to the fall of former strongman leader Suharto and helped usher in democracy.
