Judd–Ofelt intensity parameters from absorption spectrum of any lanthanide can be calculated by the RELIC application software. Judd–Ofelt intensity parameters and derived quantities (oscillator strengths, radiative transition probabilities, luminescence branching ratios, excited state radiative lifetimes, and estimates of quantum efficiencies) from the emission spectrum of Eu doped compounds, can be obtained by the JOES application software. Theoretical Judd-Ofelt intensity parameters for Eu can be obtained using the LUMPAC software. Additionally, the JOYSpectra web platform provides these parameters for all Ln ions.