Beta Profiles
iPad Air 13-inch (M4)

IPSW · iPad

iPad Air 13-inch (M4) IPSW Downloads

Every iPadOS restore image published for the iPad Air 13-inch (M4) — 34 builds from iPadOS 26.3.1 to iPadOS 27.0 RC, newest first, with signing status, size and SHA-256.

Identifier iPad16,10Identifier iPad16,11 Chip M4 Released 2026 Newest signed iPadOS 27.0 RC

Firmware for the iPad Air 13-inch (M4)

Signing status checked September 12, 2026. Downloads are Apple's own servers.

VersionSigningReleasedSize
27.0 RC
24A435
 Signed September 9, 2026 11.65 GB What's new Download 11.65 GB
FilenameiPad16,10,iPad16,11,iPad16,8,iPad16,9_27.0_24A435_Restore.ipsw SHA-256b3ea5e322fb44b2508a4e5d45ab6e0bb5e87204887d2d369879e213c184dd201 Direct URLhttps://updates.cdn-apple.com/2026FallFCS/27371c3a-7606-4f30-9c4c-ce44b262bb73/iPad16,10,iPad16,11,iPad16,8,iPad16,9_27.0_24A435_Restore.ipsw Size11,654,137,278 bytes (11.65 GB)
26.6.2
23G90
 Signed September 8, 2026 10.60 GB Download 10.60 GB
FilenameiPad16,10,iPad16,11,iPad16,8,iPad16,9_26.6.2_23G90_Restore.ipsw SHA-2562316970b279661947a9851d1987a94ebe46292b78f26d4d30214f84dcf5aa800 Direct URLhttps://updates.cdn-apple.com/2026SummerFCS/e24d21fc-b70e-4d7b-8d89-1341ef80bd93/iPad16,10,iPad16,11,iPad16,8,iPad16,9_26.6.2_23G90_Restore.ipsw Size10,600,342,486 bytes (10.60 GB)
27.0 beta 8
24A5430a
 Signed August 31, 2026 11.58 GB What's new Download 11.58 GB
FilenameiPad16,10,iPad16,11,iPad16,8,iPad16,9_27.0_24A5430a_Restore.ipsw SHA-2564c6a2ddf7b7641a89dfe19de04d20fbd27b0ddbc8dc72064c019d578df129cb0 Direct URLhttps://updates.cdn-apple.com/2026SpringSeed/a8fb8466-aac5-4fe3-abca-d86fde0a839a/iPad16,10,iPad16,11,iPad16,8,iPad16,9_27.0_24A5430a_Restore.ipsw Size11,577,662,398 bytes (11.58 GB)
27.0 beta 7
24A5424a
 Signed August 24, 2026 11.58 GB What's new Download 11.58 GB
FilenameiPad16,10,iPad16,11,iPad16,8,iPad16,9_27.0_24A5424a_Restore.ipsw SHA-256a51cd6484a3a77f99d0ebe1f8ac788f4f7f7036d6f5861828782a39fc6ec0804 Direct URLhttps://updates.cdn-apple.com/2026SpringSeed/38c6f435-0f9a-488a-acee-a18388b5e914/iPad16,10,iPad16,11,iPad16,8,iPad16,9_27.0_24A5424a_Restore.ipsw Size11,577,702,407 bytes (11.58 GB)
27.0 beta 6
24A5418b
 Signed August 17, 2026 11.58 GB What's new Download 11.58 GB
FilenameiPad16,10,iPad16,11,iPad16,8,iPad16,9_27.0_24A5418b_Restore.ipsw SHA-2566bd879ba01f3ebaa150777c4385d848c890c4cd431a85dd26f24b1af86950ee9 Direct URLhttps://updates.cdn-apple.com/2026SpringSeed/347face1-c2bf-47a6-8178-d8450316d35a/iPad16,10,iPad16,11,iPad16,8,iPad16,9_27.0_24A5418b_Restore.ipsw Size11,577,815,266 bytes (11.58 GB)
26.6.1
23G83
 Signed August 17, 2026 10.60 GB Download 10.60 GB
FilenameiPad16,10,iPad16,11,iPad16,8,iPad16,9_26.6.1_23G83_Restore.ipsw SHA-2564533908806ee3f1df43ac6d2ccd4176eb7445cf103168bf80f3da6181c8eb44f Direct URLhttps://updates.cdn-apple.com/2026SummerFCS/fullrestores/140-73628/38FCA642-846E-401B-A5C4-EE152B7160D8/iPad16,10,iPad16,11,iPad16,8,iPad16,9_26.6.1_23G83_Restore.ipsw Size10,600,410,535 bytes (10.60 GB)
27.0 beta 5
24A5408d
 Signed August 10, 2026 11.58 GB What's new Download 11.58 GB
FilenameiPad16,10,iPad16,11,iPad16,8,iPad16,9_27.0_24A5408d_Restore.ipsw SHA-2561756aa13135dfb344575a9c7281afda9758160f6c4743d029938c73202747e04 Direct URLhttps://updates.cdn-apple.com/2026SpringSeed/fullrestores/140-91891/203B0C1E-5C78-4954-947C-2F4DD1B7C175/iPad16,10,iPad16,11,iPad16,8,iPad16,9_27.0_24A5408d_Restore.ipsw Size11,578,313,757 bytes (11.58 GB)
26.6.1 RC
23G82
 Signed August 10, 2026 10.60 GB Download 10.60 GB
FilenameiPad16,10,iPad16,11,iPad16,8,iPad16,9_26.6.1_23G82_Restore.ipsw SHA-256755af87493c169fe38ee449778ba9eeaf49e7dfd01ff15993a42f113448ee115 Direct URLhttps://updates.cdn-apple.com/2026SummerFCS/fullrestores/140-87654/85AC5162-3F8A-48C8-A9B6-CC008AC7B73A/iPad16,10,iPad16,11,iPad16,8,iPad16,9_26.6.1_23G82_Restore.ipsw Size10,600,301,926 bytes (10.60 GB)
26.6
23G71
 Unsigned July 27, 2026 10.60 GB Download 10.60 GB
FilenameiPad16,10,iPad16,11,iPad16,8,iPad16,9_26.6_23G71_Restore.ipsw SHA-2567b54a2c856fd35242d5e2db18acf3bcf28a9644b984a0d7460482f26e74f38d5 Direct URLhttps://updates.cdn-apple.com/2026SummerFCS/fullrestores/140-57389/3E66DF05-DE9E-4467-AE04-3488C561494C/iPad16,10,iPad16,11,iPad16,8,iPad16,9_26.6_23G71_Restore.ipsw Size10,600,232,907 bytes (10.60 GB)
27.0 beta 4
24A5390f
 Signed July 20, 2026 11.71 GB What's new Download 11.71 GB
FilenameiPad16,10,iPad16,11,iPad16,8,iPad16,9_27.0_24A5390f_Restore.ipsw SHA-25602ce78d34730409e7202436f22efa08a4501e7678d16d50835a2c01b88c92ce0 Direct URLhttps://updates.cdn-apple.com/2026SpringSeed/fullrestores/140-57798/D1395B18-FF37-4DFF-A540-36C73EAE3300/iPad16,10,iPad16,11,iPad16,8,iPad16,9_27.0_24A5390f_Restore.ipsw Size11,711,752,301 bytes (11.71 GB)
27.0 beta 3
24A5380l
 Signed July 13, 2026 11.64 GB Download 11.64 GB
FilenameiPad16,10,iPad16,11,iPad16,8,iPad16,9_27.0_24A5380l_Restore.ipsw SHA-256b6690305e42c984ae58253ec956f1ea053bf6375bd4cf7f94e7060cb52ba491d Direct URLhttps://updates.cdn-apple.com/2026SpringSeed/fullrestores/140-39266/24382477-66B7-4FD4-9243-D025FBF1E226/iPad16,10,iPad16,11,iPad16,8,iPad16,9_27.0_24A5380l_Restore.ipsw Size11,642,324,516 bytes (11.64 GB)
26.6 beta 5
23G5065a
 Unsigned July 13, 2026 10.60 GB Download 10.60 GB
FilenameiPad16,10,iPad16,11,iPad16,8,iPad16,9_26.6_23G5065a_Restore.ipsw SHA-2565e527d3f6d783252cb63cacc4d82dea9b9d4376db9d190fac7cc720ada363c5b Direct URLhttps://updates.cdn-apple.com/2026SpringSeed/fullrestores/140-45208/B185C29A-3AA6-4EAD-A2A7-C92C30BA3D19/iPad16,10,iPad16,11,iPad16,8,iPad16,9_26.6_23G5065a_Restore.ipsw Size10,600,441,392 bytes (10.60 GB)
27.0 beta 3
24A5380h
 Signed July 6, 2026 11.64 GB Download 11.64 GB
FilenameiPad16,10,iPad16,11,iPad16,8,iPad16,9_27.0_24A5380h_Restore.ipsw SHA-256bef9fccd3ed5c893062c82b3219be778c4b2f0b694e3f5d1c1350aa26d68c910 Direct URLhttps://updates.cdn-apple.com/2026SpringSeed/fullrestores/140-36336/3C3C6A3E-F822-470E-83F3-4168DCC60180/iPad16,10,iPad16,11,iPad16,8,iPad16,9_27.0_24A5380h_Restore.ipsw Size11,642,252,591 bytes (11.64 GB)
26.6 beta 4
23G5057c
 Unsigned July 6, 2026 10.61 GB Download 10.61 GB
FilenameiPad16,10,iPad16,11,iPad16,8,iPad16,9_26.6_23G5057c_Restore.ipsw SHA-2568e71cfcf9907eb693765e4093f035d04fd0867e9aafa25c215850254e3659ed4 Direct URLhttps://updates.cdn-apple.com/2026SpringSeed/fullrestores/140-29718/5A73C0CA-7AAC-47B5-83D9-C62ED37F9E71/iPad16,10,iPad16,11,iPad16,8,iPad16,9_26.6_23G5057c_Restore.ipsw Size10,605,086,436 bytes (10.61 GB)
26.6 beta 3
23G5052d
 Unsigned June 29, 2026 10.61 GB Download 10.61 GB
FilenameiPad16,10,iPad16,11,iPad16,8,iPad16,9_26.6_23G5052d_Restore.ipsw SHA-2562c3ce4cf0805b3803a9a9eb4236d41043fc6ca19e2e944b1201c1f8b5172894e Direct URLhttps://updates.cdn-apple.com/2026SpringSeed/fullrestores/140-24630/79B11498-CB32-49B6-9BD2-B48D158A49BC/iPad16,10,iPad16,11,iPad16,8,iPad16,9_26.6_23G5052d_Restore.ipsw Size10,605,099,311 bytes (10.61 GB)
26.5.2
23F84
 Unsigned June 29, 2026 10.47 GB Download 10.47 GB
FilenameiPad16,10,iPad16,11,iPad16,8,iPad16,9_26.5.2_23F84_Restore.ipsw SHA-256a51400957b4e13be42b2db30d0a1c524e0643e669877a47b8bef3cea6821d43d Direct URLhttps://updates.cdn-apple.com/2026SpringFCS/fullrestores/140-25895/8F23C74D-A34E-4B42-9CE5-5D3A51B677C0/iPad16,10,iPad16,11,iPad16,8,iPad16,9_26.5.2_23F84_Restore.ipsw Size10,469,944,982 bytes (10.47 GB)
27.0 beta 2
24A5370h
 Signed June 22, 2026 11.84 GB Download 11.84 GB
FilenameiPad16,10,iPad16,11,iPad16,8,iPad16,9_27.0_24A5370h_Restore.ipsw SHA-256ff2cf15beda1f3f092c5e574eddbbb0922c50ec50a6b9390b235ee32248b41b9 Direct URLhttps://updates.cdn-apple.com/2026SpringSeed/fullrestores/140-22066/16E49774-1CB6-49C5-AB86-B863BFB31E58/iPad16,10,iPad16,11,iPad16,8,iPad16,9_27.0_24A5370h_Restore.ipsw Size11,841,805,172 bytes (11.84 GB)
26.6 beta 2
23G5043d
 Unsigned June 15, 2026 10.74 GB Download 10.74 GB
FilenameiPad16,10,iPad16,11,iPad16,8,iPad16,9_26.6_23G5043d_Restore.ipsw SHA-25635f8f2f362b0db98d42af6c41c9aa8e6061ea4243245e3f81c6f5b2dd511327a Direct URLhttps://updates.cdn-apple.com/2026SpringSeed/fullrestores/140-05334/02C94BCB-0173-4C44-BFFA-FD7ECFAB6096/iPad16,10,iPad16,11,iPad16,8,iPad16,9_26.6_23G5043d_Restore.ipsw Size10,739,753,835 bytes (10.74 GB)
27.0 beta
24A5355q
 Signed June 8, 2026 11.84 GB What's new Download 11.84 GB
FilenameiPad16,10,iPad16,11,iPad16,8,iPad16,9_27.0_24A5355q_Restore.ipsw SHA-256a6ae6ef8b222914e602540287214c4ee1d54807b2e077122558b3da0500fc552 Direct URLhttps://updates.cdn-apple.com/2026SpringSeed/fullrestores/122-99552/4F9BE21E-25AA-4612-9485-BCD62CBC6319/iPad16,10,iPad16,11,iPad16,8,iPad16,9_27.0_24A5355q_Restore.ipsw Size11,839,852,505 bytes (11.84 GB)
26.6 beta
23G5028e
 Unsigned May 26, 2026 10.74 GB What's new Download 10.74 GB
FilenameiPad16,10,iPad16,11,iPad16,8,iPad16,9_26.6_23G5028e_Restore.ipsw SHA-256e1e821f6d48503891f04bad9d5e48aa1a535310739fd65d50d9177a020e1e42d Direct URLhttps://updates.cdn-apple.com/2026SpringSeed/fullrestores/122-82422/D5DCD483-5B06-4FBE-BE7A-34A24F1BEA8E/iPad16,10,iPad16,11,iPad16,8,iPad16,9_26.6_23G5028e_Restore.ipsw Size10,739,521,376 bytes (10.74 GB)
26.5
23F77
 Unsigned May 11, 2026 10.47 GB What's new Download 10.47 GB
FilenameiPad16,10,iPad16,11,iPad16,8,iPad16,9_26.5_23F77_Restore.ipsw SHA-2561fd5e9f2ac97cda98144355db2cbeca76035bfd3d0318268f6cc7fe437a22035 Direct URLhttps://updates.cdn-apple.com/2026SpringFCS/fullrestores/122-37240/1A37ACA0-E7F4-4856-9C36-66D8FDEE0AF2/iPad16,10,iPad16,11,iPad16,8,iPad16,9_26.5_23F77_Restore.ipsw Size10,469,854,742 bytes (10.47 GB)
26.5 RC
23F75
 Unsigned May 4, 2026 10.47 GB What's new Download 10.47 GB
FilenameiPad16,10,iPad16,11,iPad16,8,iPad16,9_26.5_23F75_Restore.ipsw SHA-256a9a976950ff536f95753d4f865c0895b3656c9ce3208d69fc1b52d9a10d5ffe1 Direct URLhttps://updates.cdn-apple.com/2026SpringFCS/fullrestores/122-37759/158DB299-0C01-4449-9EB5-E7F12EF07E08/iPad16,10,iPad16,11,iPad16,8,iPad16,9_26.5_23F75_Restore.ipsw Size10,469,769,164 bytes (10.47 GB)
26.5 beta 4
23F5069b
 Unsigned April 27, 2026 10.47 GB Download 10.47 GB
FilenameiPad16,10,iPad16,11,iPad16,8,iPad16,9_26.5_23F5069b_Restore.ipsw SHA-256157516cec7b8e9cd340d409d4e4cf86a4fc9d77d58d1ba524e5458196c710f89 Direct URLhttps://updates.cdn-apple.com/2026SpringSeed/fullrestores/122-71816/8336B28C-FED7-441A-BD99-FD232219FCA0/iPad16,10,iPad16,11,iPad16,8,iPad16,9_26.5_23F5069b_Restore.ipsw Size10,465,838,919 bytes (10.47 GB)
26.4.2
23E261
 Unsigned April 22, 2026 10.47 GB Download 10.47 GB
FilenameiPad16,10,iPad16,11,iPad16,8,iPad16,9_26.4.2_23E261_Restore.ipsw SHA-2563603ca95cc1ed201bc81c0fb82805f23854ef7f52d7e451a7882542833acf924 Direct URLhttps://updates.cdn-apple.com/2026SpringFCS/fullrestores/122-60837/045547AA-C7E0-466B-8988-BDE26526FD07/iPad16,10,iPad16,11,iPad16,8,iPad16,9_26.4.2_23E261_Restore.ipsw Size10,469,507,661 bytes (10.47 GB)
26.5 beta 3
23F5059e
 Unsigned April 20, 2026 10.47 GB Download 10.47 GB
FilenameiPad16,10,iPad16,11,iPad16,8,iPad16,9_26.5_23F5059e_Restore.ipsw SHA-256bd5495f33817df8b1ca243fa4d87d4e64cd347abbc5a27a5129c9facf7a29566 Direct URLhttps://updates.cdn-apple.com/2026SpringSeed/fullrestores/122-54802/43DF714B-79A4-471A-B5E7-107F96D60124/iPad16,10,iPad16,11,iPad16,8,iPad16,9_26.5_23F5059e_Restore.ipsw Size10,465,876,618 bytes (10.47 GB)
26.5 beta 2
23F5054h
 Unsigned April 13, 2026 10.47 GB Download 10.47 GB
FilenameiPad16,10,iPad16,11,iPad16,8,iPad16,9_26.5_23F5054h_Restore.ipsw SHA-256171ce8fea42d9b52aeb0f77fea47fe78359aee4baff9e6f66a5955687ed6c8ca Direct URLhttps://updates.cdn-apple.com/2026SpringSeed/fullrestores/122-42754/D28E3BE8-8B15-4455-9408-DC03622E9A48/iPad16,10,iPad16,11,iPad16,8,iPad16,9_26.5_23F5054h_Restore.ipsw Size10,474,623,970 bytes (10.47 GB)
26.5 beta 2
23F5054d
 Unsigned April 13, 2026 10.47 GB Download 10.47 GB
FilenameiPad16,10,iPad16,11,iPad16,8,iPad16,9_26.5_23F5054d_Restore.ipsw SHA-2561e6c65c7ad07e7aa9eff72d082f08a725f3daa11edc897c66376be83be641ca6 Direct URLhttps://updates.cdn-apple.com/2026SpringSeed/fullrestores/122-36783/16B68534-A838-4E1B-8D48-52CCF65365ED/iPad16,10,iPad16,11,iPad16,8,iPad16,9_26.5_23F5054d_Restore.ipsw Size10,474,611,018 bytes (10.47 GB)
26.4.1
23E254
 Unsigned April 8, 2026 10.47 GB Download 10.47 GB
FilenameiPad16,10,iPad16,11,iPad16,8,iPad16,9_26.4.1_23E254_Restore.ipsw SHA-256c4cd602e921159993f1b1c8b2c032a15abf8f20a93616f4debdd21e55f74332a Direct URLhttps://updates.cdn-apple.com/2026SpringFCS/fullrestores/122-28536/F53A43D6-12F1-41B9-99D5-94EB6DFFF3A7/iPad16,10,iPad16,11,iPad16,8,iPad16,9_26.4.1_23E254_Restore.ipsw Size10,469,437,106 bytes (10.47 GB)
26.5 beta
23F5043k
 Unsigned April 3, 2026 10.47 GB Download 10.47 GB
FilenameiPad16,10,iPad16,11,iPad16,8,iPad16,9_26.5_23F5043k_Restore.ipsw SHA-2565aa987228c29c61a9a22cab49201ca4f55f2cebcc832de245c4202e66f986d74 Direct URLhttps://updates.cdn-apple.com/2026SpringSeed/fullrestores/122-26387/913F82CC-2EFA-47D8-A358-34C7CAE5B45D/iPad16,10,iPad16,11,iPad16,8,iPad16,9_26.5_23F5043k_Restore.ipsw Size10,465,958,924 bytes (10.47 GB)
26.5 beta
23F5043g
 Unsigned March 30, 2026 10.47 GB Download 10.47 GB
FilenameiPad16,10,iPad16,11,iPad16,8,iPad16,9_26.5_23F5043g_Restore.ipsw SHA-256987eca598a007c21a50074e8c5b5bafb405c96e677f885bc04ca298f9744f4fc Direct URLhttps://updates.cdn-apple.com/2026SpringSeed/fullrestores/122-22239/4AC04753-2498-4696-86B8-C08A4BA41335/iPad16,10,iPad16,11,iPad16,8,iPad16,9_26.5_23F5043g_Restore.ipsw Size10,465,956,751 bytes (10.47 GB)
26.4
23E246
 Unsigned March 24, 2026 10.47 GB Download 10.47 GB
FilenameiPad16,10,iPad16,11,iPad16,8,iPad16,9_26.4_23E246_Restore.ipsw SHA-2561a87fda19fceae05e9d908e958996d625b26e1dd50fab2bd2b89caac877124dc Direct URLhttps://updates.cdn-apple.com/2026SpringFCS/fullrestores/122-06080/B055FD74-E975-4A98-B189-00A269F1A3FC/iPad16,10,iPad16,11,iPad16,8,iPad16,9_26.4_23E246_Restore.ipsw Size10,469,435,029 bytes (10.47 GB)
26.4 RC
23E244
 Unsigned March 18, 2026 10.47 GB Download 10.47 GB
FilenameiPad16,10,iPad16,11,iPad16,8,iPad16,9_26.4_23E244_Restore.ipsw SHA-256cb5642b35154c88482830e6d8125e0b0ef439ce4c72c711283425fab891d5f33 Direct URLhttps://updates.cdn-apple.com/2026SpringFCS/fullrestores/122-04325/C916779B-6DA3-47B7-AAC3-EDB831785B1F/iPad16,10,iPad16,11,iPad16,8,iPad16,9_26.4_23E244_Restore.ipsw Size10,469,508,304 bytes (10.47 GB)
26.4 beta 4
23E5234a
 Unsigned March 9, 2026 10.47 GB Download 10.47 GB
FilenameiPad16,10,iPad16,11,iPad16,8,iPad16,9_26.4_23E5234a_Restore.ipsw SHA-2566c8c790832b577f5f8b7d918e706038af4d0eac8974ecb0abbccbfb7b439ec18 Direct URLhttps://updates.cdn-apple.com/2026WinterSeed/fullrestores/047-86645/8AA23BF2-82D2-4ECC-B71D-62C1E74B4B72/iPad16,10,iPad16,11,iPad16,8,iPad16,9_26.4_23E5234a_Restore.ipsw Size10,469,576,825 bytes (10.47 GB)
26.3.1
23D8133
 Unsigned March 4, 2026 10.25 GB Download 10.25 GB
FilenameiPad16,10,iPad16,11,iPad16,8,iPad16,9_26.3.1_23D8133_Restore.ipsw SHA-25661d7142456f0077557f688640b462103b3fb325636e9a18dee950c8dfce2e561 Direct URLhttps://updates.cdn-apple.com/2026WinterFCS/fullrestores/047-89615/138070F3-1066-4710-9DA1-8506A49114D8/iPad16,10,iPad16,11,iPad16,8,iPad16,9_26.3.1_23D8133_Restore.ipsw Size10,246,580,131 bytes (10.25 GB)

How to restore the iPad Air 13-inch (M4)

Four steps, and the one that matters most is the first.

Back up first

A restore erases the device. Make an archived backup in Finder or the Apple Devices app — an iCloud backup taken on a newer version cannot be restored onto an older one. Our backup guide covers the difference.

Get the file for your exact model

Check Settings → General → About → Model Name, then download the IPSW for that device. The download shows the file size; compare it with the SHA-256 under Details if you want to be certain the file is intact.

Restore in Finder or Apple Devices

Connect with a cable, select the device, then hold Option (Mac) or Shift (Windows) and click Restore to choose the .ipsw. Update keeps your data but only works upward; Restore erases and is how you downgrade.

Set up or restore your backup

After the restore the device starts fresh. Restore the backup you made — only if it came from the same or an older version than the one you just installed.

Questions? Answers.

Which iPad Air 13-inch (M4) firmware can I install right now?

Apple is currently signing 13 of the 34 builds listed for the iPad Air 13-inch (M4); the newest is iPadOS 27.0 RC (24A435). Use the Signed filter to see only those — an unsigned file will be rejected at the end of the restore.

How do I find my iPad Air model?

Settings → General → About shows the Model Name. Every iPad Air 13-inch (M4) has the identifier iPad16,10 or iPad16,11, and model number A3461, A3462, A3464 on the back or in About. The Wi-Fi and Cellular variants use the same restore image.

What does "signed" mean?

Apple's servers must approve a firmware before a device will accept it, and Apple only approves the builds it is currently shipping. A signed file can be restored today; an unsigned one is rejected at the end of the process, however you obtained it. Signing status changes without notice, usually within days of a newer release, which is why this catalogue rechecks it automatically.

Will I lose my data?

A Restore erases the device — that is what makes a downgrade possible. An Update with an IPSW keeps your data, but only when moving to a newer version. Either way, make an archived backup on a computer first; an iCloud backup taken on a newer version will not restore onto an older one.

Where do these files come from?

Every download link points directly at Apple's content network (updates.cdn-apple.com). The catalogue — which file belongs to which device, its size and its SHA-256 — is assembled from Apple's own software catalogs by way of AppleDB, and nothing is re-hosted or modified here.