At 6pm the rain started to fall, but no one budged. It was clear this would be a party to remember.

Jubilant Melburnians gathered at Trades Hall on Wednesday night to celebrate the same-sex marriage postal survey result.

By 7.30pm, Victoria Police announced the party had reached capacity, as inside the barricades the booze flowed and the celebrations began.

Spanish tourists Natalia Quesnel, 20, and Joshua Burge, 25, were first to arrive at Trades Hall at 4pm, draped in yellow feather boas and covered with glitter.

They'd watched the decision announced at home in Brunswick before heading to join the crowds.

The couple had been surprised to learn same-sex marriage was not yet legal in Australia. Spain approved gay unions in 2005.

"Australia is such a forward, modern, open, multicultural country, especially with Sydney and Mardi Gras," Joshua said.

"We were shocked how many people were against it."

Joshua Burge and Natalia Quesnel from Spain pose for a selfie in Lygon Street. Photo: Darrian Traynor

Viana Van Eyk arrived at trades hall carrying a sign that read "Abbott can kiss my perky lesbian ass".

The 26-year-old from Melbourne watched the news on Wednesday morning, holding hands with her flatmate, thoughts of Donald Trump and Brexit fuelling her anxiety.

When the yes vote was announced, they both cried.

Van Eyk has been carrying the same sign to gay marriage rallies for three years.

Reinforced several times with packing tape, the sign has accompanied her through four different houses.

But, as Van Eyk points out, "we're still not there yet".

"I'll hang it up when we can get married," she said.

Van Eyk said she was relieved with the decision but "disgusted" at the 40 per cent against and "disgusted" that there was a vote in the first place.

She said the plebiscite had emboldened "far-right arseholes" to voice bigoted opinions.

"The plebiscite made people feel it was okay to say no. It's not okay to be a bigot," she said.

Van Eyk is single but said she wanted the option to marry the person she loves.

"I want my white picket fence. I want the right to have a messy divorce."

In the meantime, "we're going to party hard," she says and strides off, holding her sign triumphantly.

Viana Van Eyk holds a protest poster she has carried throughout the campaign. Photo: Darrian Traynor

Rebecca Scott and her partner Kate brought their 10-year-old son Will to the celebration, "for him to feel for one night the minority becomes the majority".

Will is the only child with gay parents at the school. He didn't expect to go today, assuming instead there would be a public holiday and a "raucous party" for the yes vote.

He still went, on the proviso there would be a party later.

"I think it's an excellent decision" he said.

"I think it should've been the decision from the start. I mean, its human rights."

Rebecca and Kate had a civil union ceremony in Canberra 11 years ago this week.

They weren't planning on getting married but will has other ideas: he's planning on playing the piano at their wedding.

Kyle Cuthbert, 20, was overcome with emotion after singing with the federation university arts academy.

"It's just this overwhelming wave of joy. Just the amount of support that we're getting," he said.

"It makes me proud to be a gay man."

Kyle only recently came out to his parents. He was still in bed Wednesday morning when he read the news of Facebook.

"I literally got up and just screamed and ran around the room," he said.

Kyle Cuthbert embraces a friend at the celebrations. Photo: Darrian Traynor

Back in the crowd, federal Opposition Leader Bill Shorten congratulated Victorians "for convincing Australia it was time for gay marriage".

"It was 20 years ago mate," came the reply, to rounds of cheering applause.

Earlier, thousands gathered on the State Library lawns to hear the survey's result.

As the ABC feed blared out across the crowd, the tension was unbearable. Some held hands, others couldn't look.

Then the nation's chief statistician said the words the crowd was waiting to hear, kicking off a joyous, city-wide party

There was colour, there was music. Kissing and proposals too, with lots of tears, as the celebration erupted.

With Tom Cowie