What does "No Thanks!" mean?

Alice: Do you want some cookies?
Bob: No thanks!

Does it mean that Bob doesn't want cookies but still is thankful or its just opposite of thanks?

Solution 1:

I always understood this to mean "no, but thanks for the offer."

Saying no would be a little blunt, so its just a polite way of refusing.

Solution 2:

It is mere politeness. When somebody offers you something that you do not need or want, you just say "No, thanks!", thus showing that you are grateful for the offer.

Solution 3:

The words no thanks always mean basically the same thing: "no, thank you [for offering it/them to me]". In spoken English, there can further emotional meaning conveyed by the intonation, but this is generally hard to indicate in written English. However, the particular case of using an exclamation point and no comma (No thanks!) is often used to suggest the intonation that conveys something like "No, I really don't want it", which might be because the speaker has never liked cookies, or is valiantly trying to stay on a diet, or has diabetes and must avoid cookies, or has already declined before.

Solution 4:

In the brief context, it is almost certainly saying "No, thank you." in an informal way, since this is a discourse between two people and especially when one is offering something 'nice' to the other.

In general discussion, people will tend to be more explicit if the meaning is intended such as..