Multi-wavelength light curves of Mrk 421 UV, Mrk 421 X-ray, Mrk 501 optical, Mrk 501 UV, and Mrk 501 X-ray. The legend shows the Swift telescope and filter used to collect the data, as well as the number of observations in each band. Each data point represents one observation. We present the full dynamic range of the data, in linear scaling, and observe higher variability at higher frequencies.