Abstract: Methods and systems for dynamically annotating a web-based document are disclosed. An example method includes receiving from a user an indication of a selected portion of a web-based document to be annotated, and receiving a user selection of an editing function to be applied to the document. An annotation window overlaying the selected portion of the document is generated and an annotation to the selected portion of the document using the selected editing function is captured in the overlaid annotation window. The annotation in the overlaid annotation window is mapped to the selected portion of the web-based document underneath the annotation window, and the annotated content and corresponding mapping information are stored in a computing device. Upon receiving a request for the web-based document which has been annotated, the web-based document is provided along with a new overlaid annotation window incorporating the stored annotated content based on the mapping information.