Abstract We examine CMIP6 simulations of Arctic sea-ice area and volume. We find that CMIP6 models produce a wide spread of mean Arctic sea-ice area, capturing the observational estimate within the multi-model ensemble spread. The CMIP6 multi-model ensemble mean provides a more realistic estimate of the sensitivity of September Arctic sea-ice area to a given amount of anthropogenic CO2 emissions and to a given amount of global warming, compared with earlier CMIP experiments. Still, most CMIP6 models fail to simulate at the same time a plausible evolution of sea-ice area and of global mean surface temperature. In the vast majority of the available CMIP6 simulations, the Arctic Ocean becomes practically sea-ice free (sea-ice area <1 million km2) in September for the first time before the year 2050 in each of the four emission scenarios SSP1-1.9, SSP1-2.6, SSP2-4.5 and SSP5-8.5 examined here.