Iranians vote on Friday to elect a new president from six candidates, including a lone reformist who hopes he can challenge the dominance of conservatives in the Islamic republic.
A presidential election had not been due until 2025, but was brought forward after ultraconservative Ebrahim Raisi died in a helicopter crash last month.
The snap poll comes at a challenging time as Iran grapples with the economic impact of international sanctions amid heightened regional tensions over the Gaza war between Israel and Tehran's ally Hamas.
In April Iran fired more than 300 missiles and drones at Israel after an air strike in Damascus blamed on Israel killed seven Revolutionary Guards.
Israel carried out a reported retaliatory strike near Isfahan.
Polling is also being held just five months before a presidential election in the United States, Iran's sworn enemy and Israel's staunch ally.
Leading contenders for Iran's second highest-ranking office are conservative parliament speaker Mohammad Bagher Ghalibaf, ultraconservative former nuclear negotiator Saeed Jalili, and the sole reformist, Massoud Pezeshkian.
The others are conservative Tehran mayor Alireza Zakani, cleric Mostafa Pourmohammadi, and incumbent vice president Amirhossein Ghazizadeh-Hashemi, the ultraconservative head of the Martyrs' Foundation.
The six have staged largely low-key campaigns, which included televised debates where they vowed to tackle economic challenges and offered varied views on Iran's relations with the West.
Ali Vaez of the International Crisis Group says the new president will also have to tackle the challenge of the deepening "fissure between the state and society".
"Nobody has presented a concrete plan of how they are going to deal with a lot of these issues," he said.
Supreme leader Ayatollah Ali Khamenei, who wields the ultimate authority in Iran, urged "high participation" on Friday.
In the 2021 election that brought Raisi to power, voters shunned the polls after many reformists and moderates were disqualified.
The turnout then was just under 49 percent -- the lowest in any presidential election in Iran.
People appear divided over whether voting will mean any key concerns being addressed.
These include the mounting effects of soaring inflation and the decline of the rial against the dollar.
"There's no way I'm voting," said Neda, an engineer who gave only her first name, in northern Tehran.
"No matter who takes the post, none of them is sympathetic with the nation. My vote won't affect anything," she told AFP.
In contrast, 60-year-old housewife Jaleh said she was rooting for reformist Pezeshkian, who comes "from the people" and could address unemployment and poverty.
Reformist figures including former president Mohammad Khatami and ex-foreign minister Mohammad Javad Zarif have endorsed Pezeshkian.
However, some Iranians view the 69-year-old reformist as lacking government experience -- he only served as health minister about 20 years ago.
Of the main contenders, Ghalibaf is a veteran politician and former member of the Islamic Revolutionary Guard Corps, ideological defenders of the republic after the 1979 revolution.
Jalili, an ultraconservative former nuclear negotiator known for his inflexible stance towards the West, seems to be attracting hardline support.
Alireza Valadkhani, a 35-year-old tax consultant, told AFP he will vote for Ghalibaf as he "is the only one who can help Iran in its current situation".
One concern among voters is whether a new president will mean a potential change to the contentious hijab law for women, particularly since the mass protests triggered by the 2022 death in custody of Mahsa Amini.
Amini, a 22-year-old Iranian Kurd, was detained for allegedly breaching Iran's dress code which makes women cover their heads and necks and wear modest clothing in public.
Since the protests, women have increasingly flouted the code. But police have toughened controls in recent months on those who ignore the rules.
Most of the candidates have been cautious in the televised debates, saying they generally opposed the use of violence against those who do not wear the mandatory headscarf.
"For 40 years, we have sought to fix the hijab, but we made the situation worse," Pezeshkian said in campaigning.
For many women, the idea of a change to the hijab laws seems far-fetched.
"It is hard for the candidates to fulfil their promises" on this, said 31-year-old Maryam, who also gave only her first name.
Neda said: "The hijab law will never be lifted since this is the Islamic republic.
"I don't think any president would be willing to change this law."
