Multi-differential jet cross sections have been measured at the LHC, for various different jet sizes and center-of-mass energies. The statistical and systematic uncertainties, with their correlations, are also evaluated. These measurements are compared with theoretical predictions based on NLO QCD with non-perturbative and electroweak corrections. More recently NNLO QCD predictions also became available and started to be compared with measurements. The impact of the correlations of experimental and theoretical uncertainties on the quantitative data/theory comparisons will be discussed.