Jailbreak Cydia Tweak Icon

What happens when a jailbreak tweak bugs out on your device and ends up in a boot loop? Do you try to reboot the device to no avail? Do you take to the internet to ask how to fix it?

How about this: try booting into a form of booting up that Saurik calls ‘No Substrate Mode,’ then uninstall the faulty tweak.

In this piece, we’ll talk about how you can use No Substrate Mode, an under-used feature of jailbroken iPhone or iPad that can truly save you from losing your precious jailbreak when you’re unable to turn on your device.

Bugs can cost you your jailbreak

It’s never a good feeling when your jailbreak tweaks bug out on you, but it happens. The jailbreak community is not only full of experienced iOS developers, but it also acts as an outlet of emerging iOS developers who are tinkering with iOS for the first time.

I’ve been in the jailbreak scene for many years, and I’ve watched developers come and go – both new and old. Although new developers will get their moment of fame when they release their first jailbreak tweak in Cydia, sometimes it comes with bugs that can make a jailbroken device unstable, or cause things to crash or bug out.

In some scenarios, bugs can be severe enough to cause what’s known as a boot loop, which is where your device won’t fully boot back up and will show the Apple Logo forever.

In this case, most people hook their device up to iTunes and restore it to factory settings. The only problem is, that will erase your jailbreak.

Nowadays, a jailbreak is hard to come by. If you update to the latest firmware, you’re out your jailbreak and there doesn’t seem to be any new jailbreak in the works at this point in time due to the silence of all the major jailbreak teams and length of time between jailbreak releases.

The long story short is, you want to avoid restoring at all costs, and Saurik, the guy behind Cydia, implemented a genius feature into jailbroken devices called No Substrate Mode, which lets you boot your device up without any instances of Cydia Substrate-based tweaks running in the background.

Using No Substrate Mode to fix a boot loop

Whenever you’re in the middle of a boot loop on your jailbroken device, you should think twice about restoring your device in iTunes.

Often times, you won’t get that jailbreak back until a new jailbreak is released because Apple has been flinging new iOS releases that aren’t jail breakable left and right for the last several months.

Instead, you can manually access No Substrate Mode while your device is in a boot loop by following these easy steps:

1) Press and hold the Power and Home buttons for 10 seconds until your device shuts off and restarts itself.

iPhone Rebooting

2) While the device is booting back up (when you see the screen with the Apple logo), press and hold the Volume Up button until you see your Lock screen.

iPhone Lock Screen

At this point, you should now have access to your device again. Keep in mind that because you’re in No Susbtrate Mode, none of your Cydia Substrate-based jailbreak tweaks will function and their settings will be missing from the Settings app.

Now is your chance to open the Cydia app and uninstall the tweak that was causing your boot loop.

After you have removed the jailbreak tweak that wreaked havoc on your jailbroken device, you can reboot your device normally. The boot loop problem should be gone, and you can go back to enjoying the rest of your jailbreak tweaks without even having to restore your device in iTunes.

Wrapping up

No Substrate Mode is a valuable feature for jailbreakers, and I’m surprised it’s as under-used as it is. When I hear horror stories about people having to restore their devices in iTunes because of a faulty tweak, I feel bad for them for not knowing this feature existed.

I’ve never actually heard of a time where No Substrate Mode couldn’t fix a boot loop issue caused by a jailbreak tweak, so it’s important that jailbreakers know this feature exists; especially if we’re going to keep this community afloat and prevent unwanted software upgrades from killing the jailbreak.

Did you know you could boot into No Substrate Mode to end a boot loop issue on a jailbroken iOS device? Share below!

UPDATE: As pointed out by an iDB reader, this mode is more accurately referred to as ‘No Substrate Mode,’ and not ‘Safe Mode,’ so we’ve edited the post to reflect that. Thank you.