A position determination module determines positions that components of content—such as individual words of textual content—will have when rendered by a layout engine. Specifically, the position determination module modifies visual attribute values of the content components such that the components when rendered will have different appearances, but the same positions, as they would if rendered without the modified visual attribute values. The position determination module then causes the layout engine to render the content with the modified visual attribute values and identifies the various values of the visual attributes within the rendered content and notes the positions at which they occur. Based on its knowledge of which visual attribute values are associated with which content components, the position determination module in turn associates the positions with the corresponding content components. Thus, positions of content components within rendered images of the content can be determined.