Apple Stops Signing iOS 15.3.1 Following iOS 15.4 Release, Downgrading No Longer Possible - MacRumors
Skip to Content

Apple Stops Signing iOS 15.3.1 Following iOS 15.4 Release, Downgrading No Longer Possible

Following the release of iOS 15.4 on March 14, Apple has stopped signing iOS 15.3.1, the previously available version of iOS that came out in February. As iOS 15.3.1 is no longer being signed, it is not possible to downgrade to that version of iOS if you've updated to iOS 15.4.

iOS 15
Apple routinely stops signing older versions of software updates after new releases come out in order to encourage customers to keep their operating systems up to date, so it is not unusual that iOS 15.3.1 is no longer being signed.

iOS 15.3.1 was a bug fix update that addressed WebKit vulnerabilities, while iOS 15.4 was a major update that added new emoji characters, Face ID with a mask support, and tons of other features. Apple has also stopped signing tvOS 15.3.

Popular Stories

Apple Lists 250 Changes Across iOS 27 and More Feature

Apple Shares List of 250 Changes Across iOS 27, macOS Golden Gate, and More

Wednesday June 10, 2026 1:34 pm PDT by
During its WWDC 2026 keynote on Monday, Apple briefly showed a slide with hundreds of new features and enhancements coming across iOS 27, macOS 27 Golden Gate, watchOS 27, tvOS 27, and visionOS 27. All of the software updates are currently available as developer betas, and they are expected to be released to all users in September. We already highlighted some of the key new features from the ...
iCloud iPhone 17 Pro

iPhone Users Who Pay for iCloud Storage Get Two New Perks on iOS 27

Tuesday June 9, 2026 11:29 am PDT by
If you pay for extra iCloud storage on your iPhone, beyond the 5GB included for free, you might receive two more perks on iOS 27 at no additional cost. First, Apple said there will be daily usage limits for some of the new and enhanced Apple Intelligence features on iOS 27, including image generation. However, the company noted that "increased access" is available with "most" iCloud+ storage ...
apple intelligence black

iPhone 17's 8GB Limit Costs It These Two Siri AI Features in iOS 27

Wednesday June 10, 2026 2:19 am PDT by
Apple this week revealed what its most advanced on-device AI model does, and the feature list is shorter than the hardware requirements might suggest. In its Siri AI announcement during WWDC 2026, Apple confirmed that the model powers two things: more expressive Siri voices and a major accuracy gain for systemwide dictation. Both require 12GB of unified memory. Among current iPhones, that ...

Top Rated Comments

Black Magic Avatar
55 months ago

I'm still on iOS 14, but it looks like I need to upgrade since a policy at work requires I am on iOS 15 in order to use the internal Wi-Fi. I am going to try to hold out for iOS 15.5.1 though.
You holding out for what? You denying yourself great features thinking you are saving yourself from bugs and headaches? You like 2 years behind the curve and you feel like that is something to brag about?
Score: 9 Votes (Like | Disagree)
Y014951 Avatar
55 months ago

What features am I missing out on exactly that are so detrimental? I have been doing this every year since iOS 11. At the end of the day, it’s about the apps. iOS is just an OS. Most of what I already need in terms of integration doesn’t require iOS 15.
I honestly don't understand the downvotes. Mr. Dee seems to be a quite active participant in the Macrumors forums so I believe he knows what features he's missing. It's his decision to update his devices (or not) after all...
Score: 7 Votes (Like | Disagree)
Black Magic Avatar
55 months ago

What features am I missing out on exactly that are so detrimental? I have been doing this every year since iOS 11. At the end of the day, it’s about the apps. iOS is just an OS. Most of what I already need in terms of integration doesn’t require iOS 15.
Your employer is trying to nudge you into the present. You are obviously missing the point.
Score: 5 Votes (Like | Disagree)
canadianreader Avatar
55 months ago
We need the right to downgrade. I hope sideloading will open that door.
Score: 4 Votes (Like | Disagree)
55 months ago
and good riddance
Score: 4 Votes (Like | Disagree)
MysteriousStain Avatar
55 months ago
I am also still on 14 because it is stable and I got tired of updating and getting bugs and battery drain. I’ve heard complaining about 15.4 so I’m still waiting for something solid.
Score: 3 Votes (Like | Disagree)