Shoreline change (SLC) is a natural phenomenon governed by erosion and accretion that has contributed to the shaping of shorelines since time immemorial. The current study aims to detect and understand the village-wise dynamics of SLC in Thiruvananthapuram district, Kerala, India, using Digital Shoreline Analysis Software (DSAS) over a couple of decades (2003–2023). Three datasets of Landsat 7 and 8 (2003, 2014, 2023) were employed to detect decadal SLC. It was inferred that there was a significant increase in the erosional and accretional pattern between 2003–2014 and 2014–2023. The endpoint rate (EPR) analysis results show a high rate of erosion with a value of greater than − 2 m/yr. High erosion was encountered in the coastal villages of Paravur-Verttu, Kozhithottam-Anchuthengu, Pudukurichi-Thumba, Sankumukham-Valithura, Punthura-Panathura, Vizhinjam-Chowara, and Karumkulam-Poovar, covering a stretch of 41 km. The annual mean EPR − 1.17 m/yr in the study area was estimated for the past two decades with a maximum erosion and accretion of − 17.45 m/yr and 16.97 m/yr, respectively. The study exhibits a significant increase in the erosional patterns in the second decade (2014–23). It intensely demands constant monitoring, and urgent coastal management solutions are the need of the hour. Furthermore, immediate mitigative measures could be beneficial to prevent coastal erosion by the stakeholders, policymakers, and government bodies.