Contrary to fake YouTube videos claiming "NO PC NO SURVEY 2025 UNLIMITED DOWNGRADE," true unsigned IPSW restoration relies on hardware exploits or bootrom vulnerabilities. These are rare and do not exist for modern iPhones (iPhone XS and newer).
Here is the reality:
| Device Age | Unsigned Restore Possible? | Free Tool Required | | :--- | :--- | :--- | | iPhone 4s – iPhone X (A5–A11 chips) | ✅ Yes, using checkm8 exploit | , iOS-OTA-Downgrader , Vieux | | iPhone XS – iPhone 14 (A12–A16) | ❌ No permanent downgrade without SHSH blobs | Limited, requires saved blobs | | iPhone 15+ (A17 Pro) | ❌ No | None |
r/LegacyJailbreak – The iPhone Wiki – IPSW.me – LeetDown GitHub Have you successfully used a free unsigned IPSW restore tool? Share your experience in the comments below (but never share download links – only tool names and official sources).