Method of transferring digital data between a client device and a server device on a communication network, said method being implemented within said server device and comprising: i) coming from the client device, receiving a request in markup format for the delivery of a digital object or part of a chosen digital object, ii) obtaining in the communication network a representation of the object requested, iii) checking whether the representation of the object thus obtained corresponds to a data compression format of the progressive type, iv) in the event of a positive check, dividing the digital object into a plurality of sub-parts, to each sub-part there being allocated a high priority rank defined according to at least one chosen criterion, and v) sending to the client device a response in markup format comprising the sub-parts of the digital object in binary format and associated priority ranks in markup format.