Latest Facebook Messenger 256 user agents:

User Agent Platform Device
Mozilla/5.0 (Linux; Android 9; vivo 1901 Build/PPR1.180610.011; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/74.0.3729.136 Mobile Safari/537.36 [FB_IAB/Orca-Android;FBAV/256.2.0.23.117;] Android 9 Y15
Mozilla/5.0 (Linux; Android 9; SM-N950F Build/PPR1.180610.011; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/80.0.3987.119 Mobile Safari/537.36 [FB_IAB/Orca-Android;FBAV/256.2.0.23.117;] Android 9 Galaxy Note 8
Mozilla/5.0 (Linux; Android 9; SM-J600F Build/PPR1.180610.011; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/80.0.3987.149 Mobile Safari/537.36 [FB_IAB/Orca-Android;FBAV/256.2.0.23.117;] Android 9 Galaxy J6
Mozilla/5.0 (Linux; Android 9; SM-G950F Build/PPR1.180610.011; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/80.0.3987.149 Mobile Safari/537.36 [FB_IAB/Orca-Android;FBAV/256.2.0.23.117;] Android 9 Galaxy S8
Mozilla/5.0 (Linux; Android 9; SM-A750FN Build/PPR1.180610.011; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/80.0.3987.132 Mobile Safari/537.36 [FB_IAB/Orca-Android;FBAV/256.1.0.22.117;] Android 9 Galaxy A7 (2018)
Mozilla/5.0 (Linux; Android 9; SM-A705FN Build/PPR1.180610.011; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/80.0.3987.149 Mobile Safari/537.36 [FB_IAB/Orca-Android;FBAV/256.2.0.23.117;] Android 9 Galaxy A70
Mozilla/5.0 (Linux; Android 9; SM-A600FN Build/PPR1.180610.011; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/80.0.3987.149 Mobile Safari/537.36 [FB_IAB/Orca-Android;FBAV/256.2.0.23.117;] Android 9 Galaxy A6
Mozilla/5.0 (Linux; Android 9; SM-A600FN Build/PPR1.180610.011; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/80.0.3987.132 Mobile Safari/537.36 [FB_IAB/Orca-Android;FBAV/256.2.0.23.117;] Android 9 Galaxy A6
Mozilla/5.0 (Linux; Android 9; SM-A505G Build/PPR1.180610.011; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/80.0.3987.149 Mobile Safari/537.36 [FB_IAB/Orca-Android;FBAV/256.2.0.23.117;] Android 9 Galaxy A50
Mozilla/5.0 (Linux; Android 9; SM-A505FN Build/PPR1.180610.011; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/80.0.3987.149 Mobile Safari/537.36 [FB_IAB/Orca-Android;FBAV/256.2.0.23.117;] Android 9 Galaxy A50
Mozilla/5.0 (Linux; Android 9; SM-A205YN Build/PPR1.180610.011; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/80.0.3987.149 Mobile Safari/537.36 [FB_IAB/Orca-Android;FBAV/256.2.0.23.117;] Android 9 Galaxy A20
Mozilla/5.0 (Linux; Android 9; SM-A205U Build/PPR1.180610.011; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/80.0.3987.149 Mobile Safari/537.36 [FB_IAB/Orca-Android;FBAV/256.2.0.23.117;] Android 9 Galaxy A20
Mozilla/5.0 (Linux; Android 9; SM-A105FN Build/PPR1.180610.011; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/80.0.3987.149 Mobile Safari/537.36 [FB_IAB/Orca-Android;FBAV/256.2.0.23.117;] Android 9 Galaxy A10
Mozilla/5.0 (Linux; Android 9; SCV37 Build/PPR1.180610.011; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/74.0.3729.136 Mobile Safari/537.36 [FB_IAB/Orca-Android;FBAV/256.2.0.23.117;] Android 9 Galaxy Note 8
Mozilla/5.0 (Linux; Android 9; RMX1821 Build/PPR1.180610.011; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/80.0.3987.149 Mobile Safari/537.36 [FB_IAB/Orca-Android;FBAV/256.2.0.23.117;] Android 9 3
Mozilla/5.0 (Linux; Android 9; Redmi Note 8T Build/PKQ1.190616.001; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/80.0.3987.149 Mobile Safari/537.36 [FB_IAB/Orca-Android;FBAV/256.2.0.23.117;] Android 9 Redmi Note 8T
Mozilla/5.0 (Linux; Android 9; Redmi Note 7 Build/PKQ1.180904.001; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/80.0.3987.149 Mobile Safari/537.36 [FB_IAB/Orca-Android;FBAV/256.2.0.23.117;] Android 9 Redmi Note 7
Mozilla/5.0 (Linux; Android 9; Redmi Note 7 Build/PKQ1.180904.001; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/80.0.3987.119 Mobile Safari/537.36 [FB_IAB/Orca-Android;FBAV/256.2.0.23.117;] Android 9 Redmi Note 7
Mozilla/5.0 (Linux; Android 9; Redmi Note 5 Build/PKQ1.180904.001; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/80.0.3987.149 Mobile Safari/537.36 [FB_IAB/Orca-Android;FBAV/256.2.0.23.117;] Android 9 Redmi Note 5
Mozilla/5.0 (Linux; Android 9; Redmi 7 Build/PKQ1.181021.001; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/80.0.3987.132 Mobile Safari/537.36 [FB_IAB/Orca-Android;FBAV/256.1.0.22.117;] Android 9 Redmi 7