Comparison between the surface gravity derived from J-PLUS (log g^J-PLUS) and Gaia EDR3 (log g^GF21) photometry. Top left panel: individual measurements (red dots) with gray error bars. The median in ten gravity intervals is marked with the white dots. Dashed line marks the one-to-one relation. Top right panel: difference between J-PLUS and Gaia surface gravity as a function of Gaia temperature. White dots mark the median difference in ten temperature intervals. Dashed line depicts identity. Bottom left panel: histogram of the difference. Bottom right panel: histogram of the error-normalized difference between J-PLUS and Gaia surface gravity. In both bottom panels, the red line shows the best Gaussian fit to the distribution, with parameters labeled in the panel.