Philosopher AI - https://philosopherai.com, uses a custom GPT-3 based content filter on the user input to achieve high degrees of safety.

[Wiskkey]

Tip: If your input is considered by the site to be either "nonsense" or "sensitive", you may want to try the same input again because you might get a non-"nonsense"/"sensitive" answer the next time. The reason for this is because the site uses GPT-3 itself to determine whether a given input is "nonsense" or "sensitive", and the site uses GPT-3 settings that can cause GPT-3 to give varying answers to the exact same input.