"In sync" is a phrase that denotes agreement or harmony between two or more things or individuals. Synonyms for this phrase include "aligned," "in step," "harmonious," "coordinated," "synchronized," "matched," "congruent," "complementary," "consistent," and "simultaneous." These synonyms emphasize the idea of everything being in order and operating smoothly, without any discrepancies or disruptions. When two people or elements are in sync, there is a sense of unity and cohesion that allows them to work well together. Using synonyms for "in sync" can add variety to your communication and make your messages more interesting to read or listen to.