I have an iPhone 4, is there a way to downgrade?

[galaksy]

I am under the impression that iOS4 was optimal for iPhone4 and after the iOS upgrade everything got slower. Is there a way to downgrade?

For example if someone still have their backups of iOS4 they could clear it out so that it comes out as a blank iOS4 without any apps?

 

[The Doctor11]

No

 

[cathyy]

It can be done if you've jailbroken your phone before and saved the SHSH blobs. I downgraded my iP4 from iOS 7 to iOS 5.1.1 using this method:

Anyway I was able to do it because I still had my old SHSH blobs saved on Cydia back from my old iOS5 jailbreak. Downloaded the IPSW and used iFaith to stitch the SHSH blob together with the IPSW. Restored it using that file and bam it worked.

This guide should work: http://www.iphonehacks.com/2013/10/downgrade-ios-7-ios-6-1-3-using-ifaith.html

 

[sunking101]

You're stuck with it I'm afraid. There's a discussion here:

https://forums.macrumors.com/threads/1633905/

 

[Crichton333]

I have an iPhone 4 lying around and iOS 7 works perfect but people do report severe lag.

 

[galaksy]

It can be done if you've jailbroken your phone before and saved the SHSH blobs. I downgraded my iP4 from iOS 7 to iOS 5.1.1 using this method:

Could you send me your own SHSH blobs?

 

[Applejuiced]

Could you send me your own SHSH blobs?

They're useless.
Every shsh blob are unique to each device and cannot be reused for other phones.
In other words you're out of luck.