SEDs of 3C 454.3 from the near-IR to the UV band at different brightness levels. The four SEDs plotted with filled symbols correspond to epochs of Swift observations: recalibrated UVOT data are displayed with squares, simultaneous optical and near-IR data from the GASP-WEBT with diamonds. The two SEDs shown with empty symbols correspond to the two XMM-Newton observations of July (blue) and December (red) 2006 (see Raiteri et al. 2007): recalibrated OM data are plotted with squares and WEBT data with diamonds. The epochs of satellite observations (JD − 2   450   000) are indicated on the right. Error bars only take measure errors into account. Cyan crosses represent observations by Neugebauer et al. (1979).