Systems and techniques are described for compressing strings by using a tree data structure. Specifically, for each string in a sequence of strings, the embodiments can traverse the tree data structure by matching characters of the string with characters associated with nodes of the tree data structure until either (1) all characters in the string have been processed, or (2) a current character in the string does not match a corresponding character in a current node of the tree data structure. Next, a first node identifier associated with the current node can be returned if all characters have been processed. Otherwise, a new node can be created in the tree data structure to store the remaining characters in the string, and a second node identifier associated with the new node in the tree data structure can be returned.