According to the WHO, tap water is safe for consumption for 16% of the country.
There is a divide between rural and urban areas, tap water is safe to drink in 26% of urban areas, while it's only safe to drink in 11% of rural areas.
Never drink tap water. Bottled water is generally safe, but check the seal is intact at purchase. Boiling water is the most efficient method of purifying it. The best chemical purifier is iodine. It should not be used by pregnant women or people who suffer with thyroid problems. Water filters should protect against viruses. Ensure your filter has a chemical barrier such as iodine and a small pore size.
According to the CDC tap water is generally not safe for consumption.
According to the Numbeo water drinkability and accessibility index, tap water has a score of 54.17 / 100 (100 being best).
Numbeo considers this score to be "Moderate"
1 adult could save about 482$ per year in Laos 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.