In the past few years, audiovisual content has become a regular feature of the websites of the on-line press, in the form of videos, sound slide shows and web reports. This article takes this phenomenon as the basis for an analysis of the innovation dynamics in journalistic formats on the internet. Are the socio-technical particularities of web publication leading to profound changes in the formats that were, to some extent, permanent in the printed press? Drawing on a corpus on four sites (LeMonde.fr, Lib?ration.fr, 20minutes.fr, and Rue89.com) and interviews with journalists and technical staff, the authors show how professionals alter traditional press formats and explore the modalities of their socio-technical embeddedness.