Techniques for web-based collaborative inking sessions via a computer network are described in this document. In one embodiment, a first computer can serialize detected pointer input at a first computer into data representing one or more ink objects individually representing an image or animation corresponding to the detected pointer input. The first computer can then transmit the data representing the serialized ink objects to the second computer via the computer network. Upon receiving the transmitted data, the second computer can de-serialize the received serialized ink objects, reconstruct the image or animation corresponding to the detected pointer input at the first computer, and surface, to a second user, the image or animation of the detected pointer input on a second web browser surfacing the same webpage on the second computer, thereby enabling a web-based collaboration session between the first and second users.