No, it's not advisable to drink the tap water.
Tap water in Bangkok is not considered safe for drinking by tourists and locals alike due to contamination risks.
High levels of bacteria, virus, and parasites are often present, which can cause waterborne illnesses like diarrhea and cholera.
Boiling or using water filters/purification tablets is recommended to make tap water safe for consumption.
Thailand is ranked as number 100 globally with a score of 51.2% in the water quality EPI research conducted by Yale University.
Bangkok's tap water primarily comes from the Chao Phraya River, treated and distributed by the Metropolitan Waterworks Authority (MWA).
The MWA also sources water from nearby rivers, canals, and creeks, as well as from groundwater wells and reservoirs.
Additionally, some tap water is imported from neighboring provinces, like Nakhon Pathom and Ayutthaya, to meet the city's growing demand.
Some public drinking fountains in Bangkok are available, but their safety and maintenance vary greatly.
Few fountains are monitored and regulated by authorities, while others may not meet proper sanitation and hygiene standards.
It's recommended to stick to bottled or filtered water or use reputable refillable water stations to ensure safe drinking water.
Here is a map showing all the locations of drinking water spots in Bangkok. You can click on each water drop to open the spot directly in Google Maps for directions.