All represent some sort of limit or restriction (限定).
| | だけ | きり | のみ | | ------------------------------- | ------ | ------ | ------ | | Only (...), nothing more | ○ | ○ | | | implies emphasis on exclusivity | ✕ | ○ | | | as much as possible | ○ | | | | exclusive to (...) | | | ○ | | used in | 口語 | | 文語 | きり puts more emphasis than だけ (強調). It is more used to show e.g. "all alone, :( "
△ クリスマスは一人だけで過ごす。 ○ クリスマスは一人きりで過ごす。 (emphasis) To spend christmas alone
だけ is the antonym of しか, but as しか can only be used in the negative, they are used similarly. Making だけ negative as well shows they are quite different however:
魚だけ食べなかった I only did not eat fish (I ate anything else)
魚しか食べなかった I did not eat anything but fish (I ate nothing else)