The availability of a few dozen GRB redshifts now allows studies of the intrinsic properties of these high energy transients. Amati et al. recently discovered a correlation between Epeak, the intrinsic peak energy of thevfvspectrum, and Eiso, the isotropic equivalent energy radiated by the source. Lamb et al. have shown that HETE‐2 data confirm and extend this correlation. We discuss here one of the consequences of this correlation: the existence of a ‘spectral standard candle’, which can be used to construct a simple redshift indicator for GRBs. © 2004 American Institute of Physics