Okay so, long story short; I’m making a sort of custom chat, but since I like my account not banned, I need to know how I can check a string using the roblox algorithm, aka check if things need to be tagged. Is there any way to do this with some kind of service?
Any custom user input that is displayed for other users to see needs to be filtered. So really that is how you know if something needs to be filtered, there is nothing that determines that for you. It is something that you need to implement with your own judgement. Here is a tutorial explaining how and when to use the filtering system: https://developer.roblox.com/en-us/articles/Text-and-Chat-Filtering.