In implementations of reviewing document designs, a document review system can import reviewer comments to a design application used to author a document design. The reviewer comments can be made by a reviewer via a review application implemented on an additional computing device other than the computing device implementing the design application. The document review system can add, via the design application, a reply comment to the reviewer comment. The reply comment can be made by a designer of the document design as part of a comment hierarchy that indicates comment sequences and comment links for the document design. The document review system can also export, to the review application, a review document representing the document design that preserves the comment hierarchy in the document design.