One single place for all the iPad firmwares of all generation models. The links provided below are stock/original firmwares and comes direct from Apple servers. Please do not ask for torrents, Google it yourself. Please note that restoring older firmware versions truly depends on available SHSH blobs saved for your device. Read the SHSH blobs Doc if you don't know what those are. CDMA versions of the firmwares are not the part of this doc. they will be provided upon request. This Doc will be updated whenever Apple release new version.
Note #2 : SHSH Blobs downgrades or restore does not imply on latest iPad models starting with iPad 2. There is no way you can restore iOS version that Apple doesn't sign on server. with that being said, we have removed links of expired iOS versions and we will only add firmware links that Apple signs.
iOS 5.1.1 (released on 27th April 2012)
iPad 1 : http://appldnld.apple.com/iOS5.1.1/041-4292.02120427.Tkk0d/iPad1,1_5.1.1_9B206_Restore.ipsw
iOS 9.3.5 (released on 25th August 2016)
iPad 2 (Wi-Fi) : http://appldnld.apple.com/iOS9.3.5/...193834D2D062/iPad2,1_9.3.5_13G36_Restore.ipsw
iPad 2 (GSM) : http://appldnld.apple.com/iOS9.3.5/...973F34D2D062/iPad2,2_9.3.5_13G36_Restore.ipsw
Revised iPad 2 : http://appldnld.apple.com/iOS9.3.5/...343E34D2D062/iPad2,4_9.3.5_13G36_Restore.ipsw
iPad 3 (Wi-Fi) : http://appldnld.apple.com/iOS9.3.5/...B63D34D2D062/iPad3,1_9.3.5_13G36_Restore.ipsw
iPad 3 (GSM) : http://appldnld.apple.com/iOS9.3.5/...1F3834D2D062/iPad3,3_9.3.5_13G36_Restore.ipsw
<strong>iPad Mini (Wi-Fi) : http://appldnld.apple.com/iOS9.3.5/...933E34D2D062/iPad2,5_9.3.5_13G36_Restore.ipsw</strong>
iPad Mini (GSM) : http://appldnld.apple.com/iOS9.3.5/...093834D2D062/iPad2,6_9.3.5_13G36_Restore.ipsw
iOS 10.3.3 (released on 19th July 2017)
iPad 4 (Wi-Fi) : http://appldnld.apple.com/ios10.3.3...00BA0AE3/iPad_32bit_10.3.3_14G60_Restore.ipsw
iPad 4 (GSM) : http://appldnld.apple.com/ios10.3.3...00BA0AE3/iPad_32bit_10.3.3_14G60_Restore.ipsw
iOS 11.2 (released on 2nd December 2017)
iPad Air (Wi-Fi) : http://appldnld.apple.com/ios11.2/0...9DC24E03F/iPad_64bit_11.2_15C114_Restore.ipsw
iPad Air (Wi-Fi+4G) : http://appldnld.apple.com/ios11.2/0...9DC24E03F/iPad_64bit_11.2_15C114_Restore.ipsw
iPad Air 2 (Wi-Fi) : http://appldnld.apple.com/ios11.2/0...F/iPad_64bit_TouchID_11.2_15C114_Restore.ipsw
iPad Air 2 (Wi-Fi +4G) : http://appldnld.apple.com/ios11.2/0...F/iPad_64bit_TouchID_11.2_15C114_Restore.ipsw
iPad Pro 12.9 (Wi-Fi) : http://appldnld.apple.com/ios11.2/0...C24E03F/iPadPro_12.9_11.2_15C114_Restore.ipsw
iPad Pro 12.9 (Cellular) : http://appldnld.apple.com/ios11.2/0...C24E03F/iPadPro_12.9_11.2_15C114_Restore.ipsw
iPad Pro 9.7 (Wi-Fi) : http://appldnld.apple.com/ios11.2/0...DC24E03F/iPadPro_9.7_11.2_15C114_Restore.ipsw
iPad Pro 9.7 (Cellular) : http://appldnld.apple.com/ios11.2/0...DC24E03F/iPadPro_9.7_11.2_15C114_Restore.ipsw
iPad 5 (2017) (Wi-Fi) : http://appldnld.apple.com/ios11.2/0...d_64bit_TouchID_ASTC_11.2_15C114_Restore.ipsw
iPad 5 (2017) (Cellular) : http://appldnld.apple.com/ios11.2/0...d_64bit_TouchID_ASTC_11.2_15C114_Restore.ipsw
iPad Pro 2nd gen 12.9 (Wi-Fi) : http://appldnld.apple.com/ios11.2/0...C24E03F/iPad_Pro_HFR_11.2_15C114_Restore.ipsw
iPad Pro 2nd gen 12.9 (Cellular) : http://appldnld.apple.com/ios11.2/0...C24E03F/iPad_Pro_HFR_11.2_15C114_Restore.ipsw
iPad Pro 10.5 (Wi-Fi) : http://appldnld.apple.com/ios11.2/0...C24E03F/iPad_Pro_HFR_11.2_15C114_Restore.ipsw
iPad Pro 10.5 (Cellular) : http://appldnld.apple.com/ios11.2/0...C24E03F/iPad_Pro_HFR_11.2_15C114_Restore.ipsw
iPad Mini :
iPad Mini 2 (Wi-Fi) : http://appldnld.apple.com/ios11.2/0...9DC24E03F/iPad_64bit_11.2_15C114_Restore.ipsw
iPad Mini 2 (Wi-Fi+4G) : http://appldnld.apple.com/ios11.2/0...9DC24E03F/iPad_64bit_11.2_15C114_Restore.ipsw
iPad Mini 3 (Wi-Fi) : http://appldnld.apple.com/ios11.2/0...F/iPad_64bit_TouchID_11.2_15C114_Restore.ipsw
iPad Mini 3 (Wi-Fi+4G) : http://appldnld.apple.com/ios11.2/0...F/iPad_64bit_TouchID_11.2_15C114_Restore.ipsw
iPad Mini 4 (Wi-Fi) : http://appldnld.apple.com/ios11.2/0...F/iPad_64bit_TouchID_11.2_15C114_Restore.ipsw
iPad Mini 4 (Wi-Fi+4G) : http://appldnld.apple.com/ios11.2/0...F/iPad_64bit_TouchID_11.2_15C114_Restore.ipsw
iOS 11.2.1 (released on 13th December 2017) (CURRENT VERSION)
iPad Air (Wi-Fi) : http://appldnld.apple.com/ios11.2.1...B2783B2/iPad_64bit_11.2.1_15C153_Restore.ipsw
iPad Air (Wi-Fi+4G) : http://appldnld.apple.com/ios11.2.1...B2783B2/iPad_64bit_11.2.1_15C153_Restore.ipsw
iPad Air 2 (Wi-Fi) : http://appldnld.apple.com/ios11.2.1...iPad_64bit_TouchID_11.2.1_15C153_Restore.ipsw
iPad Air 2 (Wi-Fi +4G) : http://appldnld.apple.com/ios11.2.1...iPad_64bit_TouchID_11.2.1_15C153_Restore.ipsw
iPad Pro 12.9 (Wi-Fi) : http://appldnld.apple.com/ios11.2.1...783B2/iPadPro_12.9_11.2.1_15C153_Restore.ipsw
iPad Pro 12.9 (Cellular) : http://appldnld.apple.com/ios11.2.1...783B2/iPadPro_12.9_11.2.1_15C153_Restore.ipsw
iPad Pro 9.7 (Wi-Fi) : http://appldnld.apple.com/ios11.2.1...2783B2/iPadPro_9.7_11.2.1_15C153_Restore.ipsw
iPad Pro 9.7 (Cellular) : http://appldnld.apple.com/ios11.2.1...2783B2/iPadPro_9.7_11.2.1_15C153_Restore.ipsw
iPad 5 (2017) (Wi-Fi) : http://appldnld.apple.com/ios11.2.1...64bit_TouchID_ASTC_11.2.1_15C153_Restore.ipsw
iPad 5 (2017) (Cellular) : http://appldnld.apple.com/ios11.2.1...64bit_TouchID_ASTC_11.2.1_15C153_Restore.ipsw
iPad Pro 2nd gen 12.9 (Wi-Fi) : http://appldnld.apple.com/ios11.2.1...783B2/iPad_Pro_HFR_11.2.1_15C153_Restore.ipsw
iPad Pro 2nd gen 12.9 (Cellular) : http://appldnld.apple.com/ios11.2.1...783B2/iPad_Pro_HFR_11.2.1_15C153_Restore.ipsw
iPad Pro 10.5 (Wi-Fi) : http://appldnld.apple.com/ios11.2.1...783B2/iPad_Pro_HFR_11.2.1_15C153_Restore.ipsw
iPad Pro 10.5 (Cellular) : http://appldnld.apple.com/ios11.2.1...783B2/iPad_Pro_HFR_11.2.1_15C153_Restore.ipsw
iPad Mini :
iPad Mini 2 (Wi-Fi) : http://appldnld.apple.com/ios11.2.1...B2783B2/iPad_64bit_11.2.1_15C153_Restore.ipsw
iPad Mini 2 (Wi-Fi+4G) : http://appldnld.apple.com/ios11.2.1...B2783B2/iPad_64bit_11.2.1_15C153_Restore.ipsw
iPad Mini 3 (Wi-Fi) : http://appldnld.apple.com/ios11.2.1...iPad_64bit_TouchID_11.2.1_15C153_Restore.ipsw
iPad Mini 3 (Wi-Fi+4G) : http://appldnld.apple.com/ios11.2.1...iPad_64bit_TouchID_11.2.1_15C153_Restore.ipsw
iPad Mini 4 (Wi-Fi) : http://appldnld.apple.com/ios11.2.1...iPad_64bit_TouchID_11.2.1_15C153_Restore.ipsw
iPad Mini 4 (Wi-Fi+4G) : http://appldnld.apple.com/ios11.2.1...iPad_64bit_TouchID_11.2.1_15C153_Restore.ipsw

Note #2 : SHSH Blobs downgrades or restore does not imply on latest iPad models starting with iPad 2. There is no way you can restore iOS version that Apple doesn't sign on server. with that being said, we have removed links of expired iOS versions and we will only add firmware links that Apple signs.
iOS 5.1.1 (released on 27th April 2012)
iPad 1 : http://appldnld.apple.com/iOS5.1.1/041-4292.02120427.Tkk0d/iPad1,1_5.1.1_9B206_Restore.ipsw
iOS 9.3.5 (released on 25th August 2016)
iPad 2 (Wi-Fi) : http://appldnld.apple.com/iOS9.3.5/...193834D2D062/iPad2,1_9.3.5_13G36_Restore.ipsw
iPad 2 (GSM) : http://appldnld.apple.com/iOS9.3.5/...973F34D2D062/iPad2,2_9.3.5_13G36_Restore.ipsw
Revised iPad 2 : http://appldnld.apple.com/iOS9.3.5/...343E34D2D062/iPad2,4_9.3.5_13G36_Restore.ipsw
iPad 3 (Wi-Fi) : http://appldnld.apple.com/iOS9.3.5/...B63D34D2D062/iPad3,1_9.3.5_13G36_Restore.ipsw
iPad 3 (GSM) : http://appldnld.apple.com/iOS9.3.5/...1F3834D2D062/iPad3,3_9.3.5_13G36_Restore.ipsw
<strong>iPad Mini (Wi-Fi) : http://appldnld.apple.com/iOS9.3.5/...933E34D2D062/iPad2,5_9.3.5_13G36_Restore.ipsw</strong>
iPad Mini (GSM) : http://appldnld.apple.com/iOS9.3.5/...093834D2D062/iPad2,6_9.3.5_13G36_Restore.ipsw
iOS 10.3.3 (released on 19th July 2017)
iPad 4 (Wi-Fi) : http://appldnld.apple.com/ios10.3.3...00BA0AE3/iPad_32bit_10.3.3_14G60_Restore.ipsw
iPad 4 (GSM) : http://appldnld.apple.com/ios10.3.3...00BA0AE3/iPad_32bit_10.3.3_14G60_Restore.ipsw
iOS 11.2 (released on 2nd December 2017)
iPad Air (Wi-Fi) : http://appldnld.apple.com/ios11.2/0...9DC24E03F/iPad_64bit_11.2_15C114_Restore.ipsw
iPad Air (Wi-Fi+4G) : http://appldnld.apple.com/ios11.2/0...9DC24E03F/iPad_64bit_11.2_15C114_Restore.ipsw
iPad Air 2 (Wi-Fi) : http://appldnld.apple.com/ios11.2/0...F/iPad_64bit_TouchID_11.2_15C114_Restore.ipsw
iPad Air 2 (Wi-Fi +4G) : http://appldnld.apple.com/ios11.2/0...F/iPad_64bit_TouchID_11.2_15C114_Restore.ipsw
iPad Pro 12.9 (Wi-Fi) : http://appldnld.apple.com/ios11.2/0...C24E03F/iPadPro_12.9_11.2_15C114_Restore.ipsw
iPad Pro 12.9 (Cellular) : http://appldnld.apple.com/ios11.2/0...C24E03F/iPadPro_12.9_11.2_15C114_Restore.ipsw
iPad Pro 9.7 (Wi-Fi) : http://appldnld.apple.com/ios11.2/0...DC24E03F/iPadPro_9.7_11.2_15C114_Restore.ipsw
iPad Pro 9.7 (Cellular) : http://appldnld.apple.com/ios11.2/0...DC24E03F/iPadPro_9.7_11.2_15C114_Restore.ipsw
iPad 5 (2017) (Wi-Fi) : http://appldnld.apple.com/ios11.2/0...d_64bit_TouchID_ASTC_11.2_15C114_Restore.ipsw
iPad 5 (2017) (Cellular) : http://appldnld.apple.com/ios11.2/0...d_64bit_TouchID_ASTC_11.2_15C114_Restore.ipsw
iPad Pro 2nd gen 12.9 (Wi-Fi) : http://appldnld.apple.com/ios11.2/0...C24E03F/iPad_Pro_HFR_11.2_15C114_Restore.ipsw
iPad Pro 2nd gen 12.9 (Cellular) : http://appldnld.apple.com/ios11.2/0...C24E03F/iPad_Pro_HFR_11.2_15C114_Restore.ipsw
iPad Pro 10.5 (Wi-Fi) : http://appldnld.apple.com/ios11.2/0...C24E03F/iPad_Pro_HFR_11.2_15C114_Restore.ipsw
iPad Pro 10.5 (Cellular) : http://appldnld.apple.com/ios11.2/0...C24E03F/iPad_Pro_HFR_11.2_15C114_Restore.ipsw
iPad Mini :
iPad Mini 2 (Wi-Fi) : http://appldnld.apple.com/ios11.2/0...9DC24E03F/iPad_64bit_11.2_15C114_Restore.ipsw
iPad Mini 2 (Wi-Fi+4G) : http://appldnld.apple.com/ios11.2/0...9DC24E03F/iPad_64bit_11.2_15C114_Restore.ipsw
iPad Mini 3 (Wi-Fi) : http://appldnld.apple.com/ios11.2/0...F/iPad_64bit_TouchID_11.2_15C114_Restore.ipsw
iPad Mini 3 (Wi-Fi+4G) : http://appldnld.apple.com/ios11.2/0...F/iPad_64bit_TouchID_11.2_15C114_Restore.ipsw
iPad Mini 4 (Wi-Fi) : http://appldnld.apple.com/ios11.2/0...F/iPad_64bit_TouchID_11.2_15C114_Restore.ipsw
iPad Mini 4 (Wi-Fi+4G) : http://appldnld.apple.com/ios11.2/0...F/iPad_64bit_TouchID_11.2_15C114_Restore.ipsw
iOS 11.2.1 (released on 13th December 2017) (CURRENT VERSION)
iPad Air (Wi-Fi) : http://appldnld.apple.com/ios11.2.1...B2783B2/iPad_64bit_11.2.1_15C153_Restore.ipsw
iPad Air (Wi-Fi+4G) : http://appldnld.apple.com/ios11.2.1...B2783B2/iPad_64bit_11.2.1_15C153_Restore.ipsw
iPad Air 2 (Wi-Fi) : http://appldnld.apple.com/ios11.2.1...iPad_64bit_TouchID_11.2.1_15C153_Restore.ipsw
iPad Air 2 (Wi-Fi +4G) : http://appldnld.apple.com/ios11.2.1...iPad_64bit_TouchID_11.2.1_15C153_Restore.ipsw
iPad Pro 12.9 (Wi-Fi) : http://appldnld.apple.com/ios11.2.1...783B2/iPadPro_12.9_11.2.1_15C153_Restore.ipsw
iPad Pro 12.9 (Cellular) : http://appldnld.apple.com/ios11.2.1...783B2/iPadPro_12.9_11.2.1_15C153_Restore.ipsw
iPad Pro 9.7 (Wi-Fi) : http://appldnld.apple.com/ios11.2.1...2783B2/iPadPro_9.7_11.2.1_15C153_Restore.ipsw
iPad Pro 9.7 (Cellular) : http://appldnld.apple.com/ios11.2.1...2783B2/iPadPro_9.7_11.2.1_15C153_Restore.ipsw
iPad 5 (2017) (Wi-Fi) : http://appldnld.apple.com/ios11.2.1...64bit_TouchID_ASTC_11.2.1_15C153_Restore.ipsw
iPad 5 (2017) (Cellular) : http://appldnld.apple.com/ios11.2.1...64bit_TouchID_ASTC_11.2.1_15C153_Restore.ipsw
iPad Pro 2nd gen 12.9 (Wi-Fi) : http://appldnld.apple.com/ios11.2.1...783B2/iPad_Pro_HFR_11.2.1_15C153_Restore.ipsw
iPad Pro 2nd gen 12.9 (Cellular) : http://appldnld.apple.com/ios11.2.1...783B2/iPad_Pro_HFR_11.2.1_15C153_Restore.ipsw
iPad Pro 10.5 (Wi-Fi) : http://appldnld.apple.com/ios11.2.1...783B2/iPad_Pro_HFR_11.2.1_15C153_Restore.ipsw
iPad Pro 10.5 (Cellular) : http://appldnld.apple.com/ios11.2.1...783B2/iPad_Pro_HFR_11.2.1_15C153_Restore.ipsw
iPad Mini :
iPad Mini 2 (Wi-Fi) : http://appldnld.apple.com/ios11.2.1...B2783B2/iPad_64bit_11.2.1_15C153_Restore.ipsw
iPad Mini 2 (Wi-Fi+4G) : http://appldnld.apple.com/ios11.2.1...B2783B2/iPad_64bit_11.2.1_15C153_Restore.ipsw
iPad Mini 3 (Wi-Fi) : http://appldnld.apple.com/ios11.2.1...iPad_64bit_TouchID_11.2.1_15C153_Restore.ipsw
iPad Mini 3 (Wi-Fi+4G) : http://appldnld.apple.com/ios11.2.1...iPad_64bit_TouchID_11.2.1_15C153_Restore.ipsw
iPad Mini 4 (Wi-Fi) : http://appldnld.apple.com/ios11.2.1...iPad_64bit_TouchID_11.2.1_15C153_Restore.ipsw
iPad Mini 4 (Wi-Fi+4G) : http://appldnld.apple.com/ios11.2.1...iPad_64bit_TouchID_11.2.1_15C153_Restore.ipsw