There are numerous blogs and websites for medievalists which have compiled a range of resources. The following list is a sample of some of the more well-known sites.
La Sociedad Española de Estudios Medievales
Reti Medieval. "Reti Medievali is a set of academic initiatives devoted to medieval studies, created in 1998 by a group of scholars from the universities of Florence, Naples, Palermo, Venice and Verona in response to the uneasiness caused by the fragmentation of historiographic languages and research subjects. In 2001 a large number of other Italian and foreign historians gathered around the initiative, willing to discuss with their peers beyond their respective chronological, thematic and disciplinary specialisations, and to experiment with ways to apply information technology to research, and to communicate knowledge."
Baptisteria Sacra Index: An Iconographical Index of Baptismal Fonts (Early Christian to Seventeenth Century) Includes images of churches, sites, and contexts for liturgical vessels.
DEEDS project of medieval charters.
Fisher Digital Collections. University of Toronto Library. University of Toronto.
Fine Art Library Red Boxes (Photograph Collection), now in the UNIVERSITY OF TORONTO INSTITUTIONAL TEACHING COLLECTIONS (UTOR ID access to institutional collection on JSTOR). This is the first image collection used for teaching in the Fine Art Department at the University of Toronto. Hundreds of photographs, some going back to the early 20th century.
Manuscript Fragments. Fisher Digital Collections. University of Toronto Library. University of Toronto.
Pontifical Institute of Mediaeval Studies Manuscript Collection. Now in the UNIVERSITY OF TORONTO INSTITUTIONAL TEACHING COLLECTIONS (UTOR ID access to institutional collection on JSTOR). University of Toronto. Login with UTOR ID .
Limestone Sculpture Provenance Project The International Centre of Medieval Art, ICMA, New York.
Swedish Medieval Art Collection. Lennart Karlsson (1933-2014). Swedish History Museum, Stockholm. Includes an inventory of all medieval art in Sweden (sculpture, wall paintings, wooden statues, roods, altars). The language is Swedish.
J. Paul Getty Museum, Los Angeles, United States. Google Arts & Culture
Israel Museum, Jerusalem, Israel. Google Arts & Culture
Palace of Versailles, Versailles, France. Google Arts & Culture
Photograph Database. Swedish National Heritage Board.
Uffizi Gallery Florence, Italy. Google Arts & Culture