All of the products in this guide have been tried and tested by the Live Science team. Our testing takes into account the size of the water bottle, cost, ease of use (e.g. if the lid is easy to drink out of), portability, and whether the bottle lives up to any specific claims. For instance, if it claims to purifier tap water, we note if we can taste a difference. Finally, we check online user reviews to see what people think, and we test for any persistent problems or defects that we read about, including leakage.
As per our testing policy, we fully disclose all our findings in our reviews.