In this article, we’ll walk you through two step-by-step methods to jailbreak iOS 12.4 and, of course, include some fun illustrations along the way.
warning
All information in this article is provided for educational purposes only. The author and editorial team accept no responsibility for any consequences of reproducing the actions described here. Remember: any changes you make to your smartphone are done at your own risk.
The basics
Jailbreaking is the act of enabling unauthorized access to the iOS file system to let users install apps from unofficial repositories and explore the OS internals. This is typically achieved by exploiting vulnerabilities in iOS, which is why jailbreaks usually appear some time after a new iOS release. Apple eventually patches the discovered holes, but researchers keep finding new ways in.
All currently known jailbreak methods are generally divided into two broad categories. An untethered jailbreak is a one-and-done process: you can reboot the device as many times as you like without losing access to the filesystem. It only goes away after restoring the device’s firmware. Obviously, this kind of jailbreak isn’t available for every iOS version.
A semi-untethered jailbreak works only until the next reboot or power-off. After turning the iPhone back on, you need to run the jailbreak tool again so it can reinstall the necessary components and boot the device into a working (jailbroken) state.
The methods we’re covering today are semi-untethered and work on all iOS 12.x.x versions except 12.3, 12.3.1, 12.3.2, 12.4.1, and 12.4.2. To check which iOS version is on your device, go to Settings → General → About. The “Software Version” field shows your current OS version.
I’ll describe two ways to jailbreak a device running iOS 12—using the unc0ver and Chimera tools. Chimera doesn’t support devices with A12 or A12X chips, namely the iPhone XR, XS, XS Max, iPad Air 3, iPad Pro (11-inch, 12.9-inch 3rd gen), and iPad mini 5. For those devices you can use unc0ver—it works with all iPhone models from the 5S through the XS Max, iPad Air (1st–6th gen), iPod touch (6th, 7th gen), iPad Pro (9.7-inch, 12.9-inch, 12.9-inch 2nd gen, 10.5-inch, 11-inch, 12.9-inch 3rd gen), and iPad mini (2–5).
Just to be clear: you can’t use the methods described in this article to jailbreak a locked device. If your phone isn’t activated or it’s asking for an Apple ID password you don’t know or can’t remember, it won’t work.
Before You Start
Before we get to the actual jailbreak, there are a few prep steps to take. First, make a backup of your device just in case. Open iTunes on your computer, connect your iPhone with a cable, and when prompted, confirm the trust relationship on both the computer and the phone.
In the iTunes window, click the phone icon at the top of the left sidebar, then in the Summary view set “Automatically Back Up” to “This computer,” and click “Back Up Now.”
Now disable the phone’s passcode, Touch ID, and Face ID. Go to Settings, open Touch ID & Passcode (or Face ID & Passcode), then turn off these authentication methods.
The next important step. If two-factor authentication is enabled on the phone (and if it is, you can no longer disable it using the standard OS tools), you need to create an app-specific password that will be used during the jailbreak. You can check the status of two-factor authentication in the Settings screen: open Apple ID settings by tapping your name, then go to Password & Security.
If two-factor authentication is enabled, open the Apple ID page in your computer’s browser and sign in. Then, in Security → App-Specific Passwords, click Generate Password and follow the on-screen instructions. You’ll need to enter this password at a later step in the jailbreak process.
Apple mobile devices have a habit of downloading and installing iOS updates on their own. If an update has been downloaded but not installed, you should delete it. Go to Settings → General → iPhone (iPad) Storage, find the downloaded operating system image in the list, open it, tap Delete Update, and confirm in the popup.
Here’s a neat trick to stop your iPhone from checking for and downloading updates permanently. Open Safari, go to https://betaprofiles.com/, and use the appropriate button to download the Apple TV profile — tvOS 12. In the pop-up, tap Download anyways. The browser will warn you that the site is trying to download a configuration profile — tap Allow. Once it’s downloaded, go to Settings → General → Profile on your phone, select the tvOS Beta Software Profile you just downloaded, and tap Install. Confirm in the pop-up. The system will prompt you to restart — after the reboot, automatic update checks and downloads will be disabled.
Now go to Settings → Siri & Search, turn off all Siri features, and then restart the phone again.
Alright, with the groundwork done, it’s time to dive into the fun part—the actual hack.
warning
To successfully complete the process, iTunes must be installed on your computer. However, do not launch it until the jailbreak is finished!
Jailbreaking with unc0ver
On your computer, open a browser, go to cydiaimpactor.com, and download the version of Cydia Impactor for your operating system. The app is distributed as an archive; extract it to your drive. If you’re using Windows, run impactor., connect your iPhone to the computer, and close iTunes if it launches automatically.
Download the Undecimus-v3.7.0-b3.ipa file (you can find it, for example, on GitHub) and drag it into the Cydia Impactor window. A dialog box will appear prompting you to enter the email address you use as your Apple ID login and your account password.
If two‑factor authentication is enabled on your phone, the app will ask for an app‑specific password—remember, we generated it at appleid.apple.com. Now’s the time to use it.
The tool will handle the .ipa file and install the unc0ver app on your phone. On the iPhone itself, go to Settings → General → Profiles & Device Management, under Developer App tap the entry with the email address associated with your Apple ID, then tap Trust.
Close the Settings window, enable Airplane Mode on your phone, then launch the unc0ver app and tap the big blue Jailbreak button. The app will warn you that the system snapshot has been renamed and will prompt you to reboot—tap OK.
After the reboot, launch unc0ver on your phone again and tap Jailbreak. You may need to repeat this several times—keep trying until you see a “Jailbreak Completed” message. When it’s done, you’ll find the Cydia icon on one of your iPhone’s home screens—Cydia lets you install apps from third‑party repositories. Success! Don’t forget to turn off Airplane Mode in your phone’s settings.
Getting Started with Cydia
Basically, Cydia is ready to use right after installation. Launch the app and use it much like the App Store: tap the magnifying glass icon in the lower-right corner, enter the name of the package you’re looking for, pick it from the results, and install it.
To add new repositories to Cydia, tap the Sources button at the bottom of the screen. You’ll see a list of repositories you already have. Tap Edit in the top-right, then Add in the top-left. In the dialog that appears, enter the repository URL. You can find lists of Cydia repositories online, for example here.
For jailbroken Apple devices, users are typically advised to install the Filza File Manager to browse and manage files and folders in iOS (available from the repository https://) and NewTerm 2, a terminal app for running command‑line commands. You can also find numerous iOS tweaks in Cydia that let you modify deep system settings that aren’t accessible in the device’s normal mode.
warning
Be extremely careful when deleting files or folders on iOS with file managers, especially anything that’s part of the system. Any careless or ill‑considered action can brick your device.
Jailbreaking with Chimera
For a Chimera jailbreak, the preparatory steps are the same as those described in the previous sections. To perform the jailbreak, download Chimera-1.3.9.ipa.
The rest is straightforward: launch Cydia Impactor, connect your phone to your computer, drag the downloaded file Chimera-1. into the Cydia Impactor window, then enter your Apple ID username and password (if you have two-factor authentication enabled, use an app-specific password) and wait while the tool does its job with the package. As a result, the Chimera app icon will appear on your iPhone.
As before, go to Settings → General → Profiles & Device Management, in the Developer App section tap the line with your Apple ID email, then tap Trust. Enable Airplane Mode, launch Chimera on the phone, and tap Jailbreak. The phone will reboot automatically. After iOS starts, repeat the process until you see a prompt indicating a reboot is required, then tap OK.
As a result of these steps, you should see the Sileo icon appear on your iPhone. Sileo is another package manager for third-party iOS repositories, broadly similar to Cydia in terms of features and capabilities.
To add new repositories, tap Sources at the bottom of the Sileo window, then tap the + in the top right and enter the repository URL in the field that appears. Searching for and installing packages works just like in Cydia—use the magnifying-glass button in the bottom right.
info
Both jailbreak methods described in the article are only valid until the device is rebooted. After each power cycle, you need to relaunch the tool you installed on the device (unc0ver or Chimera) and tap the Jailbreak button.
Conclusion
As you can see, there’s nothing particularly hard about jailbreaking iOS 12—provided you follow the steps carefully. Many sources warn about the risks, but in my experience those risks are somewhat overstated. In return, a jailbreak gives you real freedom to customize the OS and install all kinds of software—exactly what a fearless researcher often needs.