OTA firmwares cannot be restored to. IPSW Downloads collects them for potential future use. They might also be useful if you're doing research.
| ✗ | Apple Watch Series 4 (44mm, LTE) | watchOS 5.2.1 (16U5079d) | March 28, 2019 | 1.3 GiB | b9dc7490186cb0ab46cce5b5bbdee0c4c29b6ffc.zip |
| ✗ | Apple Watch Series 4 (44mm, LTE) | watchOS 5.2.1 (16U5091b) | April 8, 2019 | 1.3 GiB | 667742032166d3ecdbdfeda8ef28e95e55bfd0b5.zip |
| ✗ | Apple Watch Series 4 (44mm, LTE) | watchOS 5.2.1 (16U5101c) | April 22, 2019 | 1.3 GiB | 6dd453fc242d270c9fafddcc355ce932fe2fa44f.zip |
| ✗ | Apple Watch Series 4 (44mm, LTE) | watchOS 5.2.1 (16U5110a) | April 29, 2019 | 1.3 GiB | 3688a8dac257f22e0dddb6e2b2474db80537379c.zip |
| ✗ | Apple Watch Series 4 (44mm, LTE) | watchOS 5.2.1 (16U5113a) | May 7, 2019 | 1.3 GiB | 6e237dfcd743afe17d5f4f7ab3aa4f6fc12f75f5.zip |
| ✗ | Apple Watch Series 4 (44mm, LTE) | watchOS 5.2.1 (16U113) | May 13, 2019 | 1.3 GiB | 552f3191e594ce53aca58b80e4e362754649bc54.zip |
| ✗ | Apple Watch Series 4 (40mm, LTE) | watchOS 5.2.1 (16U113) | May 13, 2019 | 1.4 GiB | 8b47b72fac8d2f8b6cf2eeb074c6c2385a2ca208.zip |
| ✗ | Apple Watch Series 4 (40mm, LTE) | watchOS 5.2.1 (16U5079d) | March 28, 2019 | 1.4 GiB | a12df5c573cdba466991aa5ae0f0ecb3563bff5e.zip |
| ✗ | Apple Watch Series 4 (40mm, LTE) | watchOS 5.2.1 (16U5091b) | April 8, 2019 | 1.4 GiB | ed361291669056a5b560b9cb7549d994e82b569c.zip |
| ✗ | Apple Watch Series 4 (40mm, LTE) | watchOS 5.2.1 (16U5101c) | April 22, 2019 | 1.4 GiB | a602cf41da69ee23e21fbc86935d7e45463c6bf2.zip |
| ✗ | Apple Watch Series 4 (40mm, LTE) | watchOS 5.2.1 (16U5110a) | April 29, 2019 | 1.4 GiB | 7ef5693c469a51b76fa1779118646c5291affc1c.zip |
| ✗ | Apple Watch Series 4 (40mm, LTE) | watchOS 5.2.1 (16U5113a) | May 7, 2019 | 1.4 GiB | 3419d394f0296659dee5cc13e47becded51979dc.zip |
| ✗ | Apple Watch Series 4 (44mm) | watchOS 5.2.1 (16U5101c) | April 22, 2019 | 1.3 GiB | 7c7ef5820bf5a0608e035b340b66c52fa3bc081a.zip |
| ✗ | Apple Watch Series 4 (44mm) | watchOS 5.2.1 (16U113) | May 13, 2019 | 1.3 GiB | d6a3d52b6bd1961a351445492389e538267e44d3.zip |
| ✗ | Apple Watch Series 4 (44mm) | watchOS 5.2.1 (16U5079d) | March 28, 2019 | 1.3 GiB | 1996858ebe497af7b42faf3a413c35613f34bfa2.zip |
| ✗ | Apple Watch Series 4 (44mm) | watchOS 5.2.1 (16U5091b) | April 8, 2019 | 1.3 GiB | a53a17f6d98c322441cf41a0a87f1c72aba76773.zip |
| ✗ | Apple Watch Series 4 (44mm) | watchOS 5.2.1 (16U5110a) | April 29, 2019 | 1.3 GiB | 1cf7fc2fabfe828c75bbc4072a7de8487c985b99.zip |
| ✗ | Apple Watch Series 4 (44mm) | watchOS 5.2.1 (16U5113a) | May 7, 2019 | 1.3 GiB | e5f567b5740d4126a0e5a625c7b2e6936f722d71.zip |
| ✗ | Apple Watch Series 4 (40mm) | watchOS 5.2.1 (16U5091b) | April 8, 2019 | 1.3 GiB | 694602c6fc574c77b61a0f45d9f54e79248497e9.zip |
| ✗ | Apple Watch Series 4 (40mm) | watchOS 5.2.1 (16U5101c) | April 22, 2019 | 1.3 GiB | 54767a5834932b2a050f1291baf6de81ba8c3ad3.zip |
| ✗ | Apple Watch Series 4 (40mm) | watchOS 5.2.1 (16U5110a) | April 29, 2019 | 1.3 GiB | 1d1d22a72bf770b38a9d138dcfd5edc78af267c5.zip |
| ✗ | Apple Watch Series 4 (40mm) | watchOS 5.2.1 (16U5113a) | May 7, 2019 | 1.3 GiB | c303b6e7dd1075e4caf027c91ea1cd4d408eac12.zip |
| ✗ | Apple Watch Series 4 (40mm) | watchOS 5.2.1 (16U113) | May 13, 2019 | 1.3 GiB | d7eb0dfb38f3afd706dc919442c771bb7d515f30.zip |
| ✗ | Apple Watch Series 4 (40mm) | watchOS 5.2.1 (16U5079d) | March 28, 2019 | 1.3 GiB | b069a58ed20583b04cb1f91c2a4415c01c3e6f0e.zip |
| ✗ | Apple Watch Series 3 (42mm) | watchOS 5.2.1 (16U113) | May 13, 2019 | 1.3 GiB | cf35ff27b0a1115d2f561c4ad05a1e38194989fa.zip |
| ✗ | Apple Watch Series 3 (42mm) | watchOS 5.2.1 (16U5079d) | March 28, 2019 | 1.3 GiB | ffb930d29b6864448035e4ceaa924f8d305ae1be.zip |
| ✗ | Apple Watch Series 3 (42mm) | watchOS 5.2.1 (16U5091b) | April 8, 2019 | 1.3 GiB | a00970ceee357aebd66868255eb190a83852cfa6.zip |
| ✗ | Apple Watch Series 3 (42mm) | watchOS 5.2.1 (16U5101c) | April 22, 2019 | 1.3 GiB | 7023ebf9e64ae22ee23219395479cb9666f8e780.zip |
| ✗ | Apple Watch Series 3 (42mm) | watchOS 5.2.1 (16U5110a) | April 29, 2019 | 1.3 GiB | 3c59bf696ddbc7055847ebbb7923306561cf9b26.zip |
| ✗ | Apple Watch Series 3 (42mm) | watchOS 5.2.1 (16U5113a) | May 7, 2019 | 1.3 GiB | e323d4af8dcfb9b78d356bddd91ecd5df43e5b2a.zip |
| ✗ | Apple Watch Series 3 (38mm) | watchOS 5.2.1 (16U5113a) | May 7, 2019 | 1.3 GiB | cdab84d813042a476b41a5f2c4f09a635db5e665.zip |
| ✗ | Apple Watch Series 3 (38mm) | watchOS 5.2.1 (16U113) | May 13, 2019 | 1.3 GiB | b33423714002c2699e34c831395e5168142a896a.zip |
| ✗ | Apple Watch Series 3 (38mm) | watchOS 5.2.1 (16U5079d) | March 28, 2019 | 1.3 GiB | 883e0430f1437066a269c3abc085f57ad8487a51.zip |
| ✗ | Apple Watch Series 3 (38mm) | watchOS 5.2.1 (16U5091b) | April 8, 2019 | 1.3 GiB | 8dec0a2cf153c5d2954a230cc13211a0a5ab5053.zip |
| ✗ | Apple Watch Series 3 (38mm) | watchOS 5.2.1 (16U5101c) | April 22, 2019 | 1.3 GiB | 75005941ce913e4e3704cc0c2691cd61cdd57494.zip |
| ✗ | Apple Watch Series 3 (38mm) | watchOS 5.2.1 (16U5110a) | April 29, 2019 | 1.3 GiB | b566a9f0128d96c0988bfa135999f2ae29cca9a1.zip |
| ✗ | Apple Watch Series 3 (42mm, LTE) | watchOS 5.2.1 (16U5079d) | March 28, 2019 | 1.3 GiB | fba3dce021f33d307240056960fdef0804dac15d.zip |
| ✗ | Apple Watch Series 3 (42mm, LTE) | watchOS 5.2.1 (16U5113a) | May 7, 2019 | 1.3 GiB | c347f84bf4fda5fe95a3cf8bf42dc718bae77379.zip |
| ✗ | Apple Watch Series 3 (42mm, LTE) | watchOS 5.2.1 (16U5091b) | April 8, 2019 | 1.3 GiB | 3a92a03777522715479dbf6af642c7c0d9895736.zip |
| ✗ | Apple Watch Series 3 (42mm, LTE) | watchOS 5.2.1 (16U5101c) | April 22, 2019 | 1.3 GiB | 80672eb8cbc7233bb8266af691cef10ca5f63736.zip |
| ✗ | Apple Watch Series 3 (42mm, LTE) | watchOS 5.2.1 (16U5110a) | April 29, 2019 | 1.3 GiB | 08c83e3373bca7267c0b61c9a50fc0f26f265354.zip |
| ✗ | Apple Watch Series 3 (42mm, LTE) | watchOS 5.2.1 (16U113) | May 13, 2019 | 1.3 GiB | a851985617ef31c15c5ef46d990f8c1d57be8db8.zip |
| ✗ | Apple Watch Series 3 (38mm, LTE) | watchOS 5.2.1 (16U113) | May 13, 2019 | 1.3 GiB | 062906fe892a72904a42d5e7d462b9b26f89acbc.zip |
| ✗ | Apple Watch Series 3 (38mm, LTE) | watchOS 5.2.1 (16U5079d) | March 28, 2019 | 1.3 GiB | fc437f5637a096ded323f99617c1e2a8c66b9711.zip |
| ✗ | Apple Watch Series 3 (38mm, LTE) | watchOS 5.2.1 (16U5091b) | April 8, 2019 | 1.3 GiB | a272add6674778d34105e23676fb42cf0bafc366.zip |
| ✗ | Apple Watch Series 3 (38mm, LTE) | watchOS 5.2.1 (16U5101c) | April 22, 2019 | 1.3 GiB | 151e38f904221b208058ef321fb597dd4ecf6614.zip |
| ✗ | Apple Watch Series 3 (38mm, LTE) | watchOS 5.2.1 (16U5110a) | April 29, 2019 | 1.3 GiB | 5f9ce32158c8eb916f9c8085b2faec58647cdd34.zip |
| ✗ | Apple Watch Series 3 (38mm, LTE) | watchOS 5.2.1 (16U5113a) | May 7, 2019 | 1.3 GiB | c784516813f5940fca5f94a913ecc0d161e6ff22.zip |
| ✗ | Apple Watch Series 1 (42mm) | watchOS 5.2.1 (16U5101c) | April 22, 2019 | 1.3 GiB | d2e2faa0b48528823ae0adb0e6d5ba7636aba715.zip |
| ✗ | Apple Watch Series 1 (42mm) | watchOS 5.2.1 (16U113) | May 13, 2019 | 1.3 GiB | 7f2f0506bfc48626712e7e8a72c002fa22a74278.zip |
| ✗ | Apple Watch Series 1 (42mm) | watchOS 5.2.1 (16U5091b) | April 8, 2019 | 1.3 GiB | b1ff06062eac0c13718fe8c175815813221b0436.zip |
| ✗ | Apple Watch Series 1 (42mm) | watchOS 5.2.1 (16U5079d) | March 28, 2019 | 1.3 GiB | 920c87b4dd20ac03db50c43388b1cbd552b38d52.zip |
| ✗ | Apple Watch Series 1 (42mm) | watchOS 5.2.1 (16U5110a) | April 29, 2019 | 1.3 GiB | fad35d4877d66a13c51962d7942a94e5d7ee2a1a.zip |
| ✗ | Apple Watch Series 1 (42mm) | watchOS 5.2.1 (16U5113a) | May 7, 2019 | 1.3 GiB | ca6d45d817b7d651cfee72a4f97232a545d1b1e5.zip |
| ✗ | Apple Watch Series 1 (38mm) | watchOS 5.2.1 (16U5113a) | May 7, 2019 | 1.3 GiB | 730cdbc9153e34fa00190a8c89fc98b4934586ab.zip |
| ✗ | Apple Watch Series 1 (38mm) | watchOS 5.2.1 (16U5091b) | April 8, 2019 | 1.3 GiB | fe7e5379a21cb8d4ffd9174cd288583204c568f0.zip |
| ✗ | Apple Watch Series 1 (38mm) | watchOS 5.2.1 (16U5101c) | April 22, 2019 | 1.3 GiB | 986cccec0f55149852fa3e4ba53f119838278bf0.zip |
| ✗ | Apple Watch Series 1 (38mm) | watchOS 5.2.1 (16U5110a) | April 29, 2019 | 1.3 GiB | fa416d15f96e42e66eb067756f029b9a58257d1f.zip |
| ✗ | Apple Watch Series 1 (38mm) | watchOS 5.2.1 (16U5079d) | March 28, 2019 | 1.3 GiB | 9083b6aa878c77a4bbab22400eb9417e82e50d36.zip |
| ✗ | Apple Watch Series 1 (38mm) | watchOS 5.2.1 (16U113) | May 13, 2019 | 1.3 GiB | 303da30c742e6cc4fafd476e062b800b81761cf2.zip |
| ✗ | Apple Watch Series 2 (42mm) | watchOS 5.2.1 (16U113) | May 13, 2019 | 1.3 GiB | 40b74fdcb5399924982dce100e4ccf3b377c93e8.zip |
| ✗ | Apple Watch Series 2 (42mm) | watchOS 5.2.1 (16U5079d) | March 28, 2019 | 1.3 GiB | 06cd1f10bd6d9e66701f66a6e74cff6007613b3c.zip |
| ✗ | Apple Watch Series 2 (42mm) | watchOS 5.2.1 (16U5091b) | April 8, 2019 | 1.3 GiB | f65656965d267c5d96caf990b797db9abc1e6b84.zip |
| ✗ | Apple Watch Series 2 (42mm) | watchOS 5.2.1 (16U5101c) | April 22, 2019 | 1.3 GiB | 37cf6ccda56e11d93b5420b1f59ef5a48d4abbed.zip |
| ✗ | Apple Watch Series 2 (42mm) | watchOS 5.2.1 (16U5110a) | April 29, 2019 | 1.3 GiB | 82e0a18a00424836fca2e33af73cc67213637309.zip |
| ✗ | Apple Watch Series 2 (42mm) | watchOS 5.2.1 (16U5113a) | May 7, 2019 | 1.3 GiB | b25eb91a6023f474f655f3499a646032815ce8f6.zip |
| ✗ | Apple Watch Series 2 (38mm) | watchOS 5.2.1 (16U113) | May 13, 2019 | 1.3 GiB | 7938b7c302eccdf45db88e68f47796f70175d8b5.zip |
| ✗ | Apple Watch Series 2 (38mm) | watchOS 5.2.1 (16U5079d) | March 28, 2019 | 1.3 GiB | 1fba7a9a1ab288bee9adbbd59a4623889671d440.zip |
| ✗ | Apple Watch Series 2 (38mm) | watchOS 5.2.1 (16U5091b) | April 8, 2019 | 1.3 GiB | 475b21cd18875fc749dc83d04a754be2bd2e88d6.zip |
| ✗ | Apple Watch Series 2 (38mm) | watchOS 5.2.1 (16U5101c) | April 22, 2019 | 1.3 GiB | e1edd37ae9f835e03d86bd2d7acde5c0580926bf.zip |
| ✗ | Apple Watch Series 2 (38mm) | watchOS 5.2.1 (16U5110a) | April 29, 2019 | 1.3 GiB | c5879ce728c1def69f87af74febb3e774f421500.zip |
| ✗ | Apple Watch Series 2 (38mm) | watchOS 5.2.1 (16U5113a) | May 7, 2019 | 1.3 GiB | 4cca2a3bc491a8eaf12ec28d18453d598422eeb4.zip |