Office workers queued for trains, restaurants and elevators and delivery riders raced from building to building as the buzz returned to Singapore's business district on Tuesday, its first day free of COVID curbs.

The city-state's high-rise commercial heart of global banks, malls and tech firms was in full swing again, with swarms of people headed to work and queues outside restaurants and crowded coffee shops after authorities lowered the pandemic alert level for the first time.

Strict limits on workplaces and gatherings were no more on Tuesday, with employees lingering outside workplaces and public transport teeming with commuters eager for normalcy after two years of containment.

"Almost full office today, first time in quite a while," said Slava Nikitin, 34, a product manager. "There were queues for elevators this morning, even though we have six elevators."

Singapore has been lauded for its speed and success in its vaccine rollout, with 93% of the population inoculated, one of the highest rates in the world, helping to limit COVID fatalities to just 1,331.

The finance hub of 5.5 million people successfully managed initial outbreaks and has maintained stringent policies on group sizes, contact-tracing, testing, travel and office work.

Though mask-wearing is still required in indoor settings or on public transport, most other curbs have been removed, to the relief of many after two long years.

"Everyone was starting to get frustrated, so it's good that we are getting back to normal now with more social interactions," said Taiwah Lim, 55, a bank employee.

"And even better with the new normal, to have the flexibility of working from home few days per week."

Also removed was testing requirement for incoming travelers vaccinated against COVID, in an effort to boost the economy, which is forecast to expand 3% to 5% this year.

It grew 7.6% in 2021, the fastest in a decade, recovering from a pandemic-induced 4.1% contraction the previous year.