Precision Tests of QCD at HERA

The study of inclusive deep inelastic scattering (DIS) and jet production processes in electron-proton scattering at HERA allows precision tests of QCD and to constrain the parton density functions (PDF) of the proton which are of particular importance for the measurements at the LHC. A selection of new measurements of structure functions and hadronic final state observables by the H1 and ZEUS collaborations is presented. Recent results on PDF fits (HERAPDF) using the inclusive DIS and jet data from both experiments are shown.