Boil, Boil, Void All Trouble
The best and most surefire way to purify tap water is to boil it.
You’ll need to heat the water to a rolling boil so it reaches 212° Fahrenheit (100° Celsius). Note: water’s boiling point is lower at higher altitudes.
Keep this in mind as you plan lodging and accommodations for your trip . . .
Will there be an electric kettle or kitchenette in your hotel room? A stove and a pot in your hostel or vacation rental? Or should you bring your own mini electric kettle like the Bonavita Dual-Voltage Kettle?
I recommend bringing an insulated thermos to store the boiled water in as it cools, preferably in a refrigerator. Be sure to keep the water covered as it cools to prevent any re-contamination.
In cases when boiling water is not an option, you can use chlorine dioxide tablets instead.
They contain the same chemical compound used by water treatment plants in many locales where the water is safe to drink.
The purified water shouldn’t have a residual taste, but in case it does, you could bring along a Brita Squeeze bottle, which filters out the taste of chlorine.