According to the WHO, tap water is safe for consumption for 100% of the country.
The tap water in Singapore is safe to drink.
According to the CDC tap water is generally safe for consumption.
According to the Numbeo water drinkability and accessibility index, tap water has a score of 86.54 / 100 (100 being best).
Numbeo considers this score to be "Very high"
1 adult could save about 964$ per year in Singapore by drinking tap water instead of buying bottled water.
๐ณ Drinking tap water would also help with reducing your plastic footprint and improve environmental pollution.
Like in most countries, water quality and accessibility differs from location to location, therefore it's the best to check the information available on that place.