ERCIM hosted the European headquarters of the World Wide Web Consortium (W3C) from 2003 until the formation of W3C Incorporated in January 2023, and has been its European Partner since then. ERCIM and W3C aim to strengthen relationships throughout Europe to better support the development of Web technology and to jointly share the results of their collaboration.

Two of the European Chapters are currently based at ERCIM institutes, namely at FORTH (Greece) and SZTAKI (Hungary). Originally, W3C Offices were located at the ERCIM institutes CWI, Fraunhofer-Gesellschaft, FORTH, SZTAKI, CNR, RISE/SICS and STFC). W3C Chapters in Europe work with their regional Web communities to promote W3C technologies in local languages, broaden W3C's geographical base, and encourage international participation in W3C activities.

As a consortium of members from many European countries, ERCIM creates a balance between European diversity and necessary homogeneity by building bridges between different cultures and facilitating the movement of technical ideas within academia and across borders. W3C is steered by its members, having interests in the Web (such as HTML5, Web Privacy and Security, Web payments, Web of Things, etc.) whereas ERCIM jointly has widespread interest in many research fields where Web standards are rarely used. ERCIM then helps to gather those Web communities and make them work together.

Moreover, ERCIM members have strong ties with industrial partners and start-up companies. This is an excellent opportunity for W3C to enlarge its cooperation with European industry, which can broaden its participation in the making and adoption of standards.

Finally, hosting W3C allows ERCIM members to benefit from the know-how and expertise of the W3C team, and to increase its visibility based on W3C's worldwide reputation. The joint efforts of ERCIM and W3C have started to increase Web research cooperation in Europe.