iOS 15 Downgrade: Yuav Ua Li Cas Zoo & Yooj Yim

Part 1. Koj puas npaj tau zoo rau iOS 15 downgrade?

Qhov tseeb iOS hloov tshiab tau raug tso tawm, tab sis cov neeg siv twb tau yws txog qee qhov ntawm nws qhov teeb meem. Txhawm rau kov yeej cov teeb meem no, koj tuaj yeem txiav txim siab ua ib qho iOS 15 downgrade. Txawm li cas los xij, koj yuav tsum tau ua ib kauj ruam rov qab thiab nkag siab nws qhov cuam tshuam. Piv txwv li, downgrade tej zaum yuav lwv tag nrho cov uas twb muaj lawm cov ntaub ntawv nyob rau hauv koj lub xov tooj nrog rau koj cov duab, apps, hu, thiab lwm yam. Yog li ntawd, nws yog ib qho tseem ceeb kom ua raws li qhov yuav tsum tau ceev faj ua ntej koj undo ib tug iOS no 15 hloov tshiab ntawm iPhone.

1.1 Ua thaub qab koj lub cuab yeej

Qhov no yog qhov tseem ceeb tshaj plaws uas koj yuav tsum tau saib xyuas ua ntej koj downgrade iOS 15 mus rau yav dhau los ruaj khov version. Thaum peb downgrade ib tug iOS no ntaus ntawv, nws yuav xaus li rho tawm tag nrho cov ntaub ntawv khaws tseg rau hauv nws. Los ntawm cov ntaub ntawv tawm mus rau cov ntaub ntawv app - koj tuaj yeem poob tag nrho cov ntsiab lus uas twb muaj lawm hauv koj lub xov tooj hauv cov txheej txheem. Yog li ntawd, txoj hauv kev zoo tshaj plaws los kawm txog kev txo qis ntawm iOS 15 mus rau qhov ruaj khov version yog los ntawm kev noj cov thaub qab ntawm koj lub xov tooj. Nyob rau hauv txoj kev no, tom qab koj ua tiav qhov downgrade, koj tuaj yeem yooj yim tau rov qab koj cov ntaub ntawv tseem ceeb los ntawm kev rov ua nws cov thaub qab.
Thaub qab iDevice nrog Dr.Fone
  • 1Txuas koj iPhone lossis iPad rau lub computer.
  • 2Xaiv hom ntaub ntawv, lossis xaiv tag nrho.
  • 3Nyem rau ntawm "Backup" khawm kom backup cov ntaub ntawv hauv zos.
Cov yam ntxwv tshwj xeeb:
  • Backup tag nrho iOS no ntaus ntawv, suav nrog nws cov neeg, hu cav, lus, duab, yeeb yaj duab, thiab lwm yam.
  • Thaub qab thiab kho koj cov ntaub ntawv los ntawm ib lub cuab yeej mus rau lwm tus (lossis ib qho iOS version rau lwm tus) yam tsis muaj teeb meem kev sib raug zoo.
  • Extract ib tug uas twb muaj lawm iCloud los yog iTunes thaub qab thiab restore nws mus rau lub ntaus ntawv ntawm peb xaiv.
  • Saib ua ntej cov ntaub ntawv los ntawm cov ntaub ntawv thaub qab los kho nws xaiv. Cov ntaub ntawv uas twb muaj lawm yuav khaws cia thaum rov kho qhov thaub qab.

Thaub qab iDevice nrog iTunes

  • 1Tua tawm ib qho tshiab version ntawm iTunes, thiab txuas lub iOS no ntaus ntawv mus rau nws.
  • 2Mus rau nws "Cov ntsiab lus" tab thiab nrhiav cov kev xaiv cuam tshuam hauv qab "Cov ntaub ntawv thaub qab" tab.
  • 3Nyem rau ntawm "Rov qab Tam Sim No" khawm kom txuag tau qhov thaub qab ntawm koj lub cuab yeej.
Tej yam yuav tsum nco ntsoov:
  • iTunes tsis tuaj yeem rov qab tau cov thaub qab ntawm cov ntawv siab dua ntawm cov qis dua. Li no koj yuav tsum coj ib tug thaub qab ntawm koj ntaus ntawv ua ntej upgraded rau iOS no 15.
  • Tsis muaj kev cai los saib ua ntej cov ntaub ntawv thiab xaiv rov qab nws.
  • iTunes deletes cov ntaub ntawv uas twb muaj lawm nyob rau hauv koj iPhone thaum restore ib tug thaub qab.

1.2 Nkag siab lub sij hawm txwv rau iOS downgrade

Tag nrho cov txheej txheem ntawm downgrading ib iOS version yog lub sij hawm-sensitive, uas ib tug ntau ntawm cov neeg siv tsis paub txog. Wb tham txog qhov no kom ntxaws.

    n
  • Yog tias koj muaj ib qho iOS beta version ntsia, ces koj tuaj yeem downgrade iOS beta mus rau yav dhau los ruaj khov version txhua lub sijhawm koj xav tau (txog rau cov pej xeem iOS version raug tso tawm).
  • Tom qab kev tso tawm ntawm cov pej xeem ruaj khov iOS version, koj tsuas muaj 14 hnub rau downgrade koj ntaus ntawv mus rau yav dhau los iOS version.

1.3 Xaiv qhov tseeb version kom downgrade los ntawm iOS 15

Qhov zoo tshaj plaws, koj tuaj yeem tsuas downgrade iOS 15 mus rau yav dhau los ruaj khov version nkaus xwb. Piv txwv li, yog tias koj xav ua ib qho iOS 15 downgrade, ces koj tsuas tuaj yeem rov qab mus rau nws qhov kev tso tawm ruaj khov yav dhau los, uas tau kos npe los ntawm Apple. Koj tuaj yeem mus ntsib IPSW.me txhawm rau txheeb xyuas seb puas muaj cov firmware sib xws.

1.4 Paub yuav ua li cas downgrade rau ib tug version tsis tau kos npe los ntawm Apple (yog tias tsim nyog)

Raws li koj paub, txhawm rau txhawm rau txo qis iOS 15, koj yuav tsum ua cov kauj ruam xav tau hauv 14 hnub ntawm nws qhov kev tso tawm. Tsis tas li ntawd, cov neeg siv tsuas tuaj yeem thim rov qab mus rau yav dhau los ruaj khov version. Txawm li cas los xij, yog tias koj tau dhau lub sijhawm 14-hnub thiab xav txo qis mus rau qhov tsis tau kos npe los ntawm Apple, ces koj yuav tsum siv lub cuab yeej thib peb. Los ntawm kev noj cov cuab yeej xws li TinyUmbrella lossis TaigOne Downgrader, koj tuaj yeem nruab ib qho kev txhawb nqa iOS no ntawm lub cuab yeej. Lawv ua raws li Apple kos npe, cia peb nruab tus kheej firmware (iOS version) ntawm iDevices.

Txawm hais tias tag nrho cov txheej txheem yuav zoo nkauj technical, thiab nws yuav tsis tau txais txiaj ntsig zoo. Txij li cov cuab yeej thib peb no tsis txhawb nqa los ntawm Apple, koj yuav tsum tau jailbreak koj lub cuab yeej ua nws. Qhov no tsis pom zoo vim nws yuav cuam tshuam rau kev lav phib xaub ntawm koj lub cuab yeej thiab koj yuav tsis muaj kev nkag mus rau cov nom iOS no thiab. Tsis tas li ntawd, nws yuav ua rau koj lub cuab yeej muaj kev cuam tshuam rau qhov tsis xav tau kev nyab xeeb hem.

Part 2. Yuav ua li cas rau Downgrade iOS 15 Safely?

Tam sim no thaum koj paub txog txhua yam yuav tsum tau ua ua ntej kom txo qis iOS 15, koj tuaj yeem ua tau raws li koj xav tau yooj yim. Qhov zoo tshaj plaws, koj tuaj yeem nqa cov kev pab ntawm iTunes lossis lwm yam cuab yeej thib peb los kawm txog kev downgrade los ntawm iOS 15. Txawm li cas los xij, nco ntsoov tias muaj cov thaub qab ntawm koj lub cuab yeej khaws cia ua ntej. Txhawm rau ua kom yooj yim rau koj, peb tau muab ob txoj kev daws teeb meem rau kev ua ib qho iOS 15 downgrade.

2.1 Ib-nias tshuaj rau Downgrade iOS 15

Cov kauj ruam hloov tshiab rau iOS 15:
  • Txuas koj ntaus ntawv iOS no rau PC thiab tso Dr.Fone.
  • Nyem rau ntawm "Kho" module, thiab mus rau qhov kev xaiv kho iOS.
  • Xaiv ob hom thiab paub meej tias koj xaiv los ntawm kev xaiv qhov tso tawm iOS version thiab nyem rau ntawm "Start".
  • Zaum rov qab thiab tos ib pliag raws li daim ntawv thov yuav pib rub tawm cov firmware sib xws rau koj lub cuab yeej iOS.
  • Nco tseg: Thov mus saib ntawm https://ipsw.me/product/iPhone kom paub tseeb tias cov firmware tau tshaj yog muaj ua ntej downgrading.

drfone android box
Dr.Fone - Qhov System Kho (iOS)
  • Hloov kho rau iOS los ntawm flashing lub firmware yav dhau los.
  • Kuj tseem tuaj yeem hloov kho iOS ntawm koj lub iDevices.
  • Tsis muaj kev vam khom rau iTunes.
  • Txhim kho tag nrho cov teeb meem hauv iOS xws li iOS khov, dawb Apple logo, thiab lwm yam.

2.2 Downgrade iOS 15 siv iTunes

Though, there are a lot of users who wish to take the assistance of iTunes to do the same. While you can perform iOS 15 downgrade with iTunes, it has its own cons. For instance, you might end up losing the existing data on your phone as it would restore your device to its factory settings. The process is also a bit technical, and you might end up damaging your device in the process.

What you need:
  • The latest version of iTunes
  • IPSW file you wish to install
Steps to downgrade iOS 15 with iTunes
  • Beforehand, Find my iPhone service on your device should be turned off. To do this, unlock it and go to its iCloud Settings > Find my iPhone to disable it. You need to enter your Apple ID and password to confirm this.
  • Now, connect your iOS device to the system and launch an updated version of iTunes on it. Click on the device icon and select your iPhone/iPad.
  • Go to its “Summary” tab and hold the Option Key (on Mac) or the Shift Key (on Windows) while clicking on the “Update” button.
  • This will open a browser window, letting you go to the location where the downloaded IPSW file is saved.
  • Select and load the IPSW file on iTunes and confirm your choice to forcefully update the connected device. Wait for a while and let iTunes complete the iOS 15 downgrade.
operate with itunes

Part 3. Best iOS 15 Downgrading Tools

As you can see, sometimes it can be tough to undo an iOS 15 update on iPhone or iPad. To make the entire process simpler, there are tons of third-party tools that you can try. Not only will they let you downgrade iOS version without losing data, but they would also yield better results. Also, if you have a jailbroken device, then you can even downgrade it to any previous iOS version. Let’s get to know more about the features and flexibility of some of these readily available tools.

3.1 Downgrading Tools for Common People (Fast & Easy to Use)

If you are a beginner and do not have a lot of technical knowledge about iOS downgrading, then consider picking either of the following tools.

3.2 Downgrading Tools for Tech-savvy Users (Complex But Can Achieve More)

If you want more flexibility with your device and have decent technical experience, then you can also explore some of these options too.

tips

What are SHSH blobs for iPhone?

Both SHSH and SHSH2 blobs are referred to digital signatures deployed by Apple on respective IPSW files. This protects the authenticity of the IPSW files and only signed software would be installed on the device. When Apple releases a new iOS version, it stops signing the previous version. In this way, users need to upgrade to the latest public iOS version. This is where previously saved SHSH blobs are used to forge these signatures in order to downgrade our devices.

Part 4. iOS 15 Downgrading Troubleshooting

4.1 iOS 15 Downgrade Failed Many Times

This is one of the most common issues that users face while downgrading their iOS devices. The chances are that while downgrading your device, the process would stop in between unexpectedly.

It happens when we try to downgrade the device to an incompatible iOS version. A faulty internet connection or low free space on the device can also trigger it.

Quick Fixes:
  • Check the iOS version: Needless to say, if you are trying to downgrade your device to an iOS version it no longer supports, then you might face unwanted issues. Ideally, you should try to downgrade iOS 15 to a previous version and not any other existing one.
  • Have a stable internet connection: An inconsistent internet connection is another prominent cause for this error. It happens when the download of the iOS update is halted in between (due to a poor connection). Therefore, make sure that the device stays connected to a working and fast internet connection for a seamless downgrading. You can go to your phone’s WiFi settings to further diagnose this.

4.2 iOS Stuck in Recovery/DFU Mode/Apple Logo

While downgrading your device, your phone might get stuck in the recovery mode, Apple logo, or the DFU mode screen. The situation might seem a bit tedious, but you can try to resolve it by forcefully restarting your phone in most of the cases.

Downgrading from an unstable version, the download process of the firmware update has been halted in between, or any other firmware related issue.

Quick Fixes:
  • Forcefully restart your device: By applying the correct key combinations, we can forcefully restart an iOS device and resolve this issue. Since it resets the current power cycle of the device, it is also known as a soft reset. If you own an iPhone 6s or an older generation phone, then long press the Power and Home button for at least 10 seconds. Users with an iPhone 7 or iPhone 7 Plus can press the Power and the Volume Down button. Keep pressing them until your phone restarts. For iPhone 8 and newer versions, you need to quick-press the Volume Up button first. Let it go and quick-press the Volume Down button. Subsequently, hold the Side button and let it go once the phone restarts.
  • Connect it to iTunes: In case if your phone is stuck in recovery or DFU mode, and you haven’t connected it to iTunes, then do the same. In no time, iTunes will automatically detect that your device is in the recovery mode and display the following prompt. Just confirm your choice and restore your device to factory settings to fix this.

4.3 iOS 15 Downgrade stuck on “Attempting data recovery”

The final step in the downgrading process is when the existing data on the device is recovered. Though, while doing so, the device might get stuck in the process and end up in the same loop.

An incompatible iOS version, loose connections, jailbroken device, lack of free storage, or any other related issue.

Quick Fixes:
  • Check whether your iPhone is jailbroken: Mostly, users get this error while performing iOS 15 downgrade on a jailbroken device. If your device is jailbroken, then you should not use iTunes to downgrade it. Instead, use a readily available tool like iFaith or TinyUmbrella to do the same.
  • Boot your iPhone in Recovery Mode: You can also take the assistance of iTunes and boot your device in the Recovery Mode to resolve this problem. To do this, just launch iTunes on your system and connect your phone to it. Now, using the correct key combinations, forcefully restart your device (already listed above). Subsequently, iTunes will detect as soon as your phone boots in the Recovery Mode. When you get the following prompt, click on the “Restore” button to reset your device.

4.4 iOS 15 Downgrade with iTunes won’t work

Most of the users take the assistance of iTunes (and an IPSW file) to downgrade iOS 15. Though, if there is a problem with the file, your device, or iTunes, then the process might not work.

An unsupported version of iTunes, corrupt IPSW file, or conflict with the device itself can result in this error.

Quick Fixes:
  • Check the IPSW file: Firstly, make sure that you have downloaded the correct IPSW file from a trusted source. Also, the IPSW file should be compatible with your iOS device else you might face this issue.
  • Disable Find my iPhone: Before you connect your device to iTunes, make sure that the Find my iPhone feature is disabled in it. To do this, go to its iCloud Settings > Find my iPhone and simply turn off this feature. This will not cause any conflict when you undo an iOS 15 update on iPhone.
  • Update iTunes: Needless to say, you should use an updated version of iTunes to downgrade iOS 15. Just launch iTunes on your system and go to Help > Check for Updates. This will make iTunes check for any available update. After finishing the update, you can restart your system and reconnect your device.

4.5 iPhone stuck in a loop trying to restore during downgrade

While restoring the device during the downgrading process, your device might get stuck. For instance, it can get stuck in a restart loop, not letting you access the device.

Lack of free space on the device, corrupt storage, incomplete update, bad IPSW file use, or any other compatibility issue.

Quick Fixes:
  • Force restart your device: This will reset the present power cycle of your device and will let you fix any minor issue related to it. To do this, you need to press certain keys on your device. We have already listed the correct key combinations to force restart a device in the previous sections.
  • Restart the process: If the downgrading process has been halted in between and your phone keeps restarting, then force restart it first. Now, connect it to iTunes or use any other third-party tool to undo an iOS 15 update on iPhone all over again.
  • Use a 3rd party tool: If nothing else seems to work, then consider using a dedicated iOS repairing tool like Dr.Fone - System Repair (iOS). It can fix all kinds of iOS and iTunes related issues without causing any harm to your device. Just launch the application and follow a simple click-through process to put your phone out of the loop and downgrade it to a stable iOS version.

4.6 iOS 15 Downgrade won’t work using SHSH

SHSH Blobs are Apple signatures that are needed to downgrade iOS 15 in a timely manner. Their absence or a wrong SHSH entity can tamper with the downgrading process.

Wrong SHSH blob, corrupt unit by a third-party dump, or an expired SHSH blob can be some of the major reasons for this.

Quick Fixes:
  • Use an SHSH blobs dumper: There are tons of readily available third-party SHSH dumpers (like iFaith) that you can try. Though, most of these applications will require a jailbroken device. You can simply connect your device or provide its model to obtain an ideal SHSH blob.
  • Obtain your device’s SHSH blob: You can connect your iPhone/iPad to the system and launch iTunes on it. Select your device and go to its Summary. Click on the “Serial Number” field a few times, till it displays the ECID number. Now, copy the ECID code and go to any online source to convert it into hexadecimal code.

4.7 Lost all data after iOS 15 Downgrade

This is one of the worst nightmares for any iOS user. After completing the downgrade, the chances are that you might end up losing all the saved photos, videos, contacts, messages, and other important files from your phone.

The process could be halted in between, a corrupt device, bad firmware, and so on. An upgrade to an unstable release of iOS can also cause data loss on your device.

Quick Fixes:
  • Use a data recovery tool ASAP: If you have suffered from an unwanted data loss on your device, then take the assistance of an iOS data recovery program . A part of the Dr.Fone toolkit, it is one of the first and the most successful data recovery tools for iOS devices. All you need to do is connect your device and launch the application. Follow a simple click-through process to extract all kinds of lost or deleted data from your device. The application will let you preview the extracted data, letting you selectively save it to the location of your choice.

4.8 Backup cannot be restored after iOS 15 downgrade

Even after losing their data while downgrading an iOS device, users try to restore an existing backup. Sadly, there are times when the previous iTunes or iCloud backup ceases to restore on the downgraded device.

The problem usually occurs due to a compatibility issue among various iOS versions. For instance, you could have taken the backup of your device when it was running on another iOS version and now you are trying to restore it on an unsupported iOS version.

Quick Fixes:
  • You can load a previous iTunes or iCloud backup using a iOS restoring tool and even preview its data on its interface. For instance, to restore an iCloud backup, you simply need to log-in to your iCloud account. The application will list the available backup files for you pick an ideal option. In this way, you can easily restore your data without erasing the existing content on your device.

Part 5. FAQs about iOS 15 Downgrade

Yes, you can downgrade iOS to a previous version signed by Apple. Users get 14 days after a public official release to do it. If you have upgraded your device to a version, then you can downgrade to a stable version easily (until 14 days after the release of its stable version).

There are all kinds of ways to undo an iOS 15 update on iPhone. If you want, you can take the assistance of iTunes to do the same. Though, to downgrade iOS 15 without losing data, consider using a more sophisticated tool like Dr.Fone - System Repair (iOS). In case if you have a jailbroken device, then you can even give tools like TinyUmbrella a go.

When we install an iOS version on the device, the Apple server asks for a digital signature to authenticate it. A signed IPSW file would have a verified signature issued by Apple, letting us upgrade/downgrade the device without any hassle. Therefore, if an IPSW file is not signed by Apple, then it will not be recognized by the server and the upgrading/downgrading process won’t be completed.

There are all kinds of SHSH dumps and readily available third-party tools that can help us force Apple’s signature and create SHSH blobs even after Apple stops signing them. Though, you should know that Apple might revoke the authentication of such SHSH blobs anytime. To do this, you need to have a jailbroken device and use a dedicated tool like iFaith or FutureRestore.

The Apple Software Program lets us test the releases of iOS before the public availability. You can join or leave the program anytime you want without spending anything. If you want to leave it, then go to the Unenroll section of the website.

apple beta program

Ideally, you can’t downgrade your device to an unsigned iOS version. This is because the Apple server won’t authenticate your downloading request without a valid SHSH blob. That is why users take the assistance of a previously saved SHSH blob to do the same. You can also use a third-party downgrading tool to do it as well.

After downgrading an iOS update, you might find an existing software profile on your device storage. To remove this, just go to your device’s Settings > General > Profile and select the iOS profile from here. Tap on the “Delete Profile” option and confirm your choice to remove it.

You can restore a previously stored SHSH blob from your device or forge Apple’s signature. There are a few third-party tools like FutureRestore that can help you do the same. You can also choose to dump your SHSH blobs in order to use them afterward. Though, in most of the cases, users have to jailbreak their device in order to do it.