Leak localization performance between rubber-based diaphragm fibre Bragg grating (FBG) pressure sensors and aluminium-based diaphragm FBG pressure sensors were compared and studied. A total of two aluminium-based and two rubber-based diaphragm FBG pressure sensors were fitted on a pipe with various leak points and sizes. Calibration test results showed that rubber-based diaphragm FBG pressure sensors are 30 times much higher as compared to aluminium-based diaphragm FBG pressure sensors at 93.2 pm/kPa and 96.6 pm/kPa. For leak localization test using negative pressure wave (NPW), rubber-based diaphragm FBG pressure sensors capable to localize accurately the leak location with percentage of error less than 10 . This is due to the high pressure resolution produced by the rubber-based diaphragm FBG pressure sensors. © 2024 Elsevier Inc.