A first krypton vs. xenon experimental comparison of the Hayabusa2 and DESTINY+ μ10 Electron Cyclotron Resonance (ECR) gridded ion sources, and their ECR neutralizer, is presented. When operating on krypton, the ion sources deliver similar current in the same propellant consumption range and provide equivalent thrust levels. Nevertheless, the system experiences about 30% of thruster efficiency loss as the neutralizer propellant demand for comparable current levels more than doubles. •The Hayabusa2 and DESTINY+ μ10 ECR ion sources deliver similar current in the same propellant consumption range operated on krypton and xenon.•Inside the ion sources, krypton can generate the largest current as it shows a delayed drop in power absorption with increased mass flow rate with respect to xenon.•The krypton propellant demand of the electron-cyclotronresonance neutralizer used by the μ10 thruster more than doubles the xenon one for comparable current levels.