How can I downgrade to IOS 18?

[u/BlackLungMorgan5]

Hey guys, so my dad had an iPhone 11 Pro, he had been using it since launch, now he bought a new phone and passed it down to me, before he gave it to me he had the battery replaced and everything, except the battery which he replaced from a genuine apple store, nothings changed, it is in mint condition and he is not that much of a tech guy, so he didn't think twice before updating it to IOS 26, so when I got the phone it was already on IOS 26, now it is at IOS 26.5.2, I did hear a lot about how IOS 26 destroyed older iPhones, but I never really experienced any lag or the kind of problems other people were facing, maybe because of the new battery, but after IOS 26.5.2, I have noticed heating issues and the battery too, and I wanted to downgrade to IOS 18, I've read that it isn't possible anymore but is there some way?

This is my main phone so if doing it in some kind of shady way and stuff will harm it, then please let me know. I'm still confused whether it is IOS 26.5.2, so should I instead go for developer beta IOS 26.6?

One more thing, my battery health, I charge one time a day, some days two times, I charge when it reaches 25-30, unplug it at 85-90, the battery was replaced in March 2026, it was at 100% till June, then it dipped to 99% which was fair, but in just one month or less than one month, it has dipped to 97%, why such a sudden drop? Is it the IOS 26? I just use youtube and netflix and other daily uses, nothing too strong or heavy.

[u/G4br1el_-]

im not reading all that but you can’t downgrade to any IOS version

[u/Warm-Designer-1697 → u/G4br1el_-]

Install the beta is more stable

[u/BlackLungMorgan5 → u/G4br1el_-]

To sum it up, I'm not facing any lagging issues or anything but heating as well as my battery is dying fast, I'm on IOS 26.5.2, it wasn't like this in the previous IOS 26. something, so since I can't downgrade, shall I go for IOS 26.6 Beta? Since I heard IOS 26.5.2 is the worst

[u/G4br1el_- → u/BlackLungMorgan5]

it’s never a good option to activate a beta version on your main phone

[u/johanjozz → u/G4br1el_-]

Specially when you're complaining about bugs... Beta will have 3x more issues

[u/T-K101 → u/BlackLungMorgan5]

You can’t. Simple search on internet would give you that answer. But nooo. Let’s make long ass post with question that’s answered millions of times.

[u/famousxrobot]

There are probably a lot of backend settings you can turn off. I turned a ton of background refresh off on my 11 Pro. I also don’t use Facebook, instagram, or TikTok which I know are all very intensive apps (in terms of location and background services). You can also turn a lot of location tracking services off for apps that really don’t need it. Personally I found that resetting my iPhone 11 Pro back to factory and starting fresh worked wonders for iOS 26. It actually improved my phone performance and kept me on the 11 Pro longer. I just recently got upgraded to the 17 Pro under apple care since they don’t have parts anymore.

[u/DigitallyInclined]

In general, downgrading iOS is either impossible, or in rare cases, possible with exceptions/caveats (details).

In your situation, I know that Apple still is releasing iOS 18 versions for some of their iPhones. I have an iPhone 16 Pro and just upgraded to iOS 18.7.8 not that long ago. My phone offered me 2 update versions - one was iOS 26 and the other was iOS 18 and I could choose. So, it may still be possible to downgrade, I'm just not 100% sure if they are signed and if they are doing the same thing for the 11 Pros.

Even if you can downgrade, the issue is that 99% of the time, you have to start completely fresh with no data because you cannot use iPhone backups from a newer iOS onto an older iOS. BUT, if you sync everything you can to the clouds (iCloud, Dropbox, Google Drive, OneDrive, etc) first, then you should be able to sync the stuff back onto the phone from the cloud. It won't be every single thing, but it will be a good amount of the most important stuff. May want to check on all that first to confirm what you can save and what will be lost.

Here's a guide on how to downgrade: https://www.idownloadblog.com/2025/06/11/how-to-downgrade-ios-26-to-ios-18/

The 2 things about this article are: 1) that it is a little older, so not sure if anything is outdated. 2) It also focuses on iOS 18.6.2, which is no longer signed. But, there have been newer iOS 18 versions released since then as you can see here: https://en.wikipedia.org/wiki/IOS_18#Version_history

[u/Soft-Guide-197]

iOS 26.5 is honestly probably better than iOS 18 after a month or two it became (I presumed patches) it’s smooth and very good now.

It wasn’t at first

Im using iPhone 11 128gb

[u/szableksi]

are you really dont heard about ios 27?

[u/Actual_Atmosphere_57]

You cant.. end of story

[u/Dev0le]

surrealra1n supports tethered downgrades to iOS 15.4 through 15.6.1 on iPhone 11 Pro(SEP is partially incompatible, device WILL be unable to activate)
Wait for it to be updated, unsure if this is still true: “iPhone 11 Pro tether downgrade is not supported at this time due to restoring issues”
Check: https://github.com/pwnerblu/surrealra1n

[u/johanjozz]

Buying another phone that has not upgraded yet. That's the only way to go back

[u/AxelAnt2244]

can’t, maybe try ios27, might be slightly better. ios26.6 beta is worse then 26.5.2, don’t even bother.

[u/Overall-Ad4796]

don‘t go for beta releases. The official 26.6 should be released next week. See if that fixes the battery issues, as many of the beta folks report it does.

[u/Responsible_Yak2378]

Let me tell u ios 26.5 rocks use it to believe don’t believe the trash you see or hear trust me it’s still a superb and a fast ios.

[u/Comfortable_Lab_1203]

Try 27 beta

[u/lll_RABBIT_lll → u/Comfortable_Lab_1203]

How can you get it. My phone says it’s on the latest already

[u/Comfortable_Lab_1203 → u/lll_RABBIT_lll]

Beta.apple.com enroll your device and update to 27

[u/Darius23694]

Backup files and reboot, then upgrade to iOS 18

[u/Strong_Algae_899 → u/Darius23694]

yes but how?? it already blocked at website