Empirical approach for investigating anisothermal sintering kinetics was proposed to analyze activation energies of two different sintering methods. This work verified that the activation energy of ZnO densification is inherently small for the cold sintering process with the aid of compatible transient chemistry. The proposed fundamental framework further contributed to improving the theoretical understanding of the cold sintering process and provided reliable kinetic data, which can be potentially used in developing a relevant analytical sintering model.