Cleaning syngas, particularly reforming tars, is still a major bottleneck to the development of gasification. In this work, syngas was simultaneously sampled and analysed downstream and upstream of a tar conversion reactor using a real syngas produced with a commercial gasifier. At 800 °C and 2 s residence time, tar conversion reached 51a% compared with only 11 % in an inert bed. The tar content in the syngas decreased from 8.1 to 4.2 g/Nm3. Almost all the tertiary tars were converted, and only benzene, toluene, and naphthalene persisted. The energy content of the syngas increased by 5 % thanks to simultaneously increase of the LHV and syngas flowrate. LHV's increase in mainly due to H2 production.