It’s Safe
In Tonga, you don't have to go about clutching your bags or peering over your shoulder. The crime rate is really low! Furthermore, deadly creatures are scarcely a concern, with the single poisonous sea snake unable to break through human skin (and hence unable to harm people). Tonga similarly has no significant illnesses. However, this is not mean that you should disregard all prudence.
Overall, it is a secure site for you as a visitor from practically all angles, but you should take all precautions to ensure your safety and security. With the development of tourism on the islands in recent years, cases of robberies, thefts, and crime, in general, have increased, which means that you as a tourist should choose wisely your accommodation to ensure that all your belongings are safe. It is also recommended to always have a mobile phone from which you will be able to call in case of emergency.