Abstract Kīlauea is a broad shield volcano built against the southeastern slope of Mauna Loa. The summit presently has a caldera that is roughly 4 km by 3.2 km wide, and walls between 0 and 120 m high. In late April 2018, an eruption involving both the summit crater and the lower East Rift Zone occurred. In this work a quasi-real-time estimation of the evolution of radiant lava flow extension starting from May 2018 for Kīlauea–Leilani eruption using satellite image data is presented. The active lava flow evolution was obtained using Copernicus Sentinel2 (S2) and USGS-Landsat8 (L8) polar satellites acquiring medium/high-spatial-resolution images (20 × 20 m and 30 × 30 m, respectively) in the vis–SWIR–TIR (Short wave infrared-thermal infra red) spectral range. Because of the Kīlauea eruption extension and duration, a multisensor approach was used in order to improve the timing of the information derived by high-spatial-resolution remote-sensed data merging two missions with different revisit times. The 2018 eruptions at Hawaii's Kīlauea Volcano developed rapidly after the initial activity centred on the Pu‘u ‘Ō‘o crater floor on 1 May followed by draining of the lava lake at Halemáumáu Overlook Crater in the following days. During the magma extrusion from the summit, earthquake swarms and ground cracking hit the Leilani Estates neighbourhood on 2 May. With the S2 and L8 sensors we followed the lava flow from 5 May up to mid August, considering also that the activity started to decline from the beginning of August. At the end of the activity, Kīlauea Volcano had experienced its largest lower East Rift Zone eruption and caldera collapse in at least 200 years.