Replo is a cross-platform utility for performing syntactically-aware diff, find, and replace operations. It is similar to IntelliJ's "structural find and replace" feature but allows for configurable grammars. With Replo, users can compare, detect, and replace idiomatic structures without worrying about irrelevant stylistic inconsistencies. Common grammars (e.g. C, C++, C#, Java, Ruby) are provided, but users can also leverage ANTLR to define their own.