This research looks into improving online web-based collaborative drawing using HTML5. Although many systems have been developed over a number of years, none of the applications released have been satisfactory for many artists; the core drawing experience was too different from a stand-alone drawing applications. Stand-alone drawing applications have better freedom of control with functions like undo and allow artists to work efficiently with hotkeys. The advent of the HTML5 Canvas Element and Websockets in recent browsers has provided new opportunities for collaborative online interaction. This research used an incremental development approach to build a prototype HTML5 drawing application providing new functionality for online collaborative drawing. The project was supported by two experienced artists throughout investigation, design, implementation and testing. The project artists helped validate design decisions and evaluate the implementation. As a result, a robust HTML5 collaborative drawing application was built. The prototype contains core drawing functionality that existing applications did not. Features include: undo and redo, free canvas transformation, complex hotkey interaction, custom canvas size support, colour wheel, and layers. All these features work smoothly in a fully synchronized network environment under a client-server model. The collaboration system uses an authoritative server structure with local prediction and re-synchronization to hide latency. Although the result is only a prototype, the evaluations from the project artists were very positive. Once more functionality targeted towards social interaction is built, the prototype will be ready for mass public testing. Although there are some issues caused by the immaturity of HTML5 technology, this project affirms its capability for collaborative web applications.