Latest Facebook 504 user agents:

User Agent Platform Device
Mozilla/5.0 (Linux; Android 11; AE9010 Build/RP1A.201005.001; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/145.0.7632.120 Mobile Safari/537.36 [FB_IAB/FB4A;FBAV/504.0.0.69.64;] Android 11 V80
Mozilla/5.0 (iPhone; CPU iPhone OS 15_8_5 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) Mobile/19H394 [FBAN/FBIOS;FBAV/504.0.0.62.85;FBBV/707243085;FBDV/iPhone8,1;FBMD/iPhone;FBSN/iOS;FBSV/15.8.5;FBSS/2;FBID/phone;FBLC/en_US;FBOP/5;FBRV/710721179;IABMV/1] iOS 15 iPhone 6s
Mozilla/5.0 (iPhone; CPU iPhone OS 26_3_1 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) Mobile/23D8133 [FBAN/FBIOS;FBAV/504.0.0.62.85;FBBV/707243085;FBDV/iPhone15,4;FBMD/iPhone;FBSN/iOS;FBSV/26.3.1;FBSS/3;FBID/phone;FBLC/en_US;FBOP/5;FBRV/710721179;IABMV/1] iOS 26 iPhone 15
Mozilla/5.0 (Linux; Android 10; Nokia C2 Tennen Build/QP1A.190711.020; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/134.0.6998.92 Mobile Safari/537.36 [FB_IAB/FB4A;FBAV/504.0.0.69.64;] Android 10 C2 Tennen
Mozilla/5.0 (Linux; Android 9; ZT216_2 Build/PPR1.180610.011; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/134.0.6998.92 Safari/537.36 [FB_IAB/FB4A;FBAV/504.0.0.69.64;IABMV/1;] Android 9 ZT216
Mozilla/5.0 (Linux; Android 9; Y9Plus Build/PPR1.180610.011; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/121.0.6167.178 Mobile Safari/537.36 [FB_IAB/FB4A;FBAV/504.0.0.69.64;] Android 9 Y9 Plus
Mozilla/5.0 (Linux; Android 9; X20 PRO Build/P00610; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/134.0.6998.92 Mobile Safari/537.36 [FB_IAB/FB4A;FBAV/504.0.0.69.64;IABMV/1;] Android 9 X20 Pro
Mozilla/5.0 (Linux; Android 9; X19 S Build/PPR1.180610.011; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/134.0.6998.92 Mobile Safari/537.36 [FB_IAB/FB4A;FBAV/504.0.0.69.64;IABMV/1;] Android 9 X19 S
Mozilla/5.0 (Linux; Android 9; U70B Build/PPR1.180610.011; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/134.0.6998.92 Mobile Safari/537.36 [FB_IAB/FB4A;FBAV/504.0.0.69.64;IABMV/1;] Android 9 U70B
Mozilla/5.0 (Linux; Android 9; U70B Build/PPR1.180610.011; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/133.0.6943.137 Mobile Safari/537.36 [FB_IAB/FB4A;FBAV/504.0.0.69.64;IABMV/1;] Android 9 U70B
Mozilla/5.0 (Linux; Android 9; U693CL Build/U693CL_01.02.05; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/134.0.6998.92 Mobile Safari/537.36 [FB_IAB/FB4A;FBAV/504.0.0.69.64;] Android 9 UMX U693CL
Mozilla/5.0 (Linux; Android 9; Trekker-X4 Build/PKQ1.190414.001; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/134.0.6998.92 Mobile Safari/537.36 [FB_IAB/FB4A;FBAV/504.0.0.69.64;IABMV/1;] FBNV/5 Android 9 Trekker-X4
Mozilla/5.0 (Linux; Android 9; Trekker-X4 Build/PKQ1.190414.001; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/134.0.6998.92 Mobile Safari/537.36 [FB_IAB/FB4A;FBAV/504.0.0.69.64;IABMV/1;] Android 9 Trekker-X4
Mozilla/5.0 (Linux; Android 9; TECNO CC9 Build/PPR1.180610.011; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/135.0.7049.111 Mobile Safari/537.36 [FB_IAB/FB4A;FBAV/504.1.0.72.107;] Android 9 Camon 12 Pro
Mozilla/5.0 (Linux; Android 9; TECNO AB7 Build/PPR1.180610.011; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/133.0.6943.121 Mobile Safari/537.36 [FB_IAB/FB4A;FBAV/504.1.0.72.107;] Android 9 Phantom 9
Mozilla/5.0 (Linux; Android 9; TBBVNC100005207 Build/PPR1.180610.011; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/134.0.6998.92 Safari/537.36 [FB_IAB/FB4A;FBAV/504.0.0.69.64;] Android 9 TBBVNC100005207
Mozilla/5.0 (Linux; Android 9; TBBVNC100005207 Build/PPR1.180610.011; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/134.0.6998.92 Safari/537.36 [FB_IAB/FB4A;FBAV/504.0.0.69.64;IABMV/1;] Android 9 TBBVNC100005207
Mozilla/5.0 (Linux; Android 9; SM-T827V Build/PPR1.180610.011; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/91.0.4472.164 Safari/537.36 [FB_IAB/FB4A;FBAV/504.0.0.69.64;] Android 9 Galaxy Tab S3 9.7" LTE
Mozilla/5.0 (Linux; Android 9; SM-T827V Build/PPR1.180610.011; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/134.0.6998.95 Safari/537.36 [FB_IAB/FB4A;FBAV/504.0.0.69.64;IABMV/1;] Android 9 Galaxy Tab S3 9.7" LTE
Mozilla/5.0 (Linux; Android 9; SM-T827V Build/PPR1.180610.011; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/134.0.6998.92 Safari/537.36 [FB_IAB/FB4A;FBAV/504.0.0.69.64;IABMV/1;] Android 9 Galaxy Tab S3 9.7" LTE