You are really asking for the difference between "it" and "that" because the answer has nothing to do with "okay". "It" and "that" are pronouns used to identify something. They can be used interchangeably without altering the meaning of a sentence. Yet, it does make a difference which one you choose because your choice of "it", "that", or "this" gives information about how you are thinking about the identified thing. So the difference between "that's okay" "it's okay" "this is okay" has no relation to the external world. The difference is only inside of the head of the speaker. By using... "that", the speaker identifies the thing as something distant, as if pointing to the thing "this", the speaker identifies the thing as something close, as if holding it in his hand "it", the speaker identifies the thing in a detached, neutral way.

Hey. So this one can be a little tricky and often can be used interchangeably. But the main difference between “That’s okay.” and “It’s okay.” is context related. For example, typically, “That’s okay.” Is used used for reassurance that something isn’t that big of a deal, or that there isn’t a problem to make a fuss about. For example: Maybe your children accidentally spilt food in the kitchen while you’re cleaning. Your children: “Mom, we’re sorry, we spilt food on the floor in the kitchen, please don’t be mad.” You: “Don’t worry, that’s okay. I’ll clean it up.” In this context “That’s okay.” Is just reassuring them that you aren’t upset and that it is okay they’ve spilt food in the kitchen because it was an accident. “It’s okay” can be used the same way. But, in some cases you might want to use “it’s okay”. Maybe your children are crying because they’ve woke up because they had a nightmare. Your children: *crying*, mommy where are you?” You: Hey, what’s going on, why are you guys crying?” Them: “We had a nightmare, we saw a monster.” You:”Don’t worry, It’s okay, Mommy’s here.” In this context you’d want to use “it’s okay” because you are reassuring them that it is okay, and that they don’t need to be upset or cry because you’re there (to protect them, in this context). Hope this helped a little bit, but in general you can use them both interchangeably regardless of the context and always be understood. 😅

i think so this is Similar