Top panel: constraints on the CPL and coupling parameters using currently available data for α measurements alone (purple contours) and in combination with Euclid forecast constraints with a ΛCDM fiducial (yellow contours for the pessimistic case and cyan contours for the optimistic case). Bottom panel: reconstruction of the mean trend in redshift of Δα/α and of the allowed 68% confidence level area, obtained interpolating the marginalized means and errors of the derived parameters described in Sect. 4. The purple dashed line and purple area refer to α measurements alone, the yellow solid line and yellow area include Euclid in the pessimistic case, while the dotted green line and green contours combine the optimistic case.