From pink tube tops to hats and even facial hair dyed in pink, straight and gay Singaporeans arrived at Speakers' Corner, a government-designated free speech park, in the colour theme picked by organisers to represent the freedom to love.

Some brought their dogs and cats in pink pet clothing and leashes.

"Singaporeans gathered here today are saying that we want to be a kinder and more inclusive society," Ivan Heng, an ambassador for the organiser Pink Dot Sg, told AFP at the park.

"More Singaporeans have come to understand that prejudice and discrimination hurts the community, our families, and the people we work with," said Heng, who is also a prominent local theatre director.

Organisers, who stressed that the event was not a protest but a public show of support for lesbian, gay, bisexual and transgender (LGBT) people, estimated that 21,000 people had attended.

It was the biggest crowd since the annual event started in 2009, when nearly 2,500 people attended.

15,000 participated in the event last year, which counts Barclays Bank, JP Morgan and Google among its corporate sponsors.

The three-hour gathering featured musical performances by Singaporean artists, and culminated with the crowd forming a giant pink dot after dusk by holding LED lights.

Lisa Sim, 29, said the event's growth in stature since its inception showed that the LGBT community is increasingly gaining social acceptance in the city-state.

"Straight Singaporeans are realising that we are no different than them, and deserve the same rights as them", said Sim, who attended the event with her lesbian partner.

Law student Akesh Abhilash, 25, said younger Singaporeans are more inclined to denounce calls from conservative segments of society to retain Section 377A, a provision in the penal code that makes it a crime for men to have sex with each other.

"The gay community does not infringe on any one's rights. It is ridiculous for others to claim to be able to dictate how they should lead their lives," he said.

While Section 377A is not enforced actively by authorities, LGBT rights campaigners still see it as a threat and demand its repeal.

Government officials maintain that the law must stay in the books because most Singaporeans are still conservative and do not accept homosexuality.

Singapore's High Court in April rejected a petition to repeal the law, whose origins go back to the 19th century when Singapore was a British colony, drawing condemnation from international rights activists.