There are a lot of phone cases on the market that claim to be the most protective, but it can be hard to know which one is actually the best. A good place to start your search is with a case that has been certified by an independent lab like Underwriters Laboratories (UL). UL certification means that a case has been tested for things like drop and impact resistance.
Another thing to look for in a protective phone case is military-grade protection. This means that the case has been tested to meet or exceed MIL-STD 810G standards. These standards are set by the U.S. Department of Defense and cover things like shock, vibration, and extreme temperatures.
Finally, you'll want to make sure that your chosen phone case includes a warranty from the manufacturer. This will give you peace of mind in knowing that if something does happen to your phone while it's in the case, you'll be covered.