If you own a newer PS4 Slim or Pro, no downgrade to 1.00 is physically possible.
Disassemble the PS4 completely to expose the motherboard. Locate the NOR chip (usually a small 8‑pin SOIC‑8 near the HDMI port) and the Syscon chip (a 64‑pin QFP chip near the power management ICs).
Tools that claim to downgrade your PS4 by simply plugging the console into a Windows PC via USB and running an .exe file. Standard USB ports on a retail PS4 cannot communicate with the core flashing interface of the Syscon chip. ps4 tool downgrade v1.00
For the vast majority of users, the safe answer is the first one. For the adventurous few who understand the risks and have the necessary skills and backups, the second path remains a fringe but documented possibility in the hardware modification scene. Whatever you choose, know the difference between a game and a system downgrade, and always, always back up your data first.
The PS4 storage architecture contains two "banks" for firmware: the active bank and the previous bank. When the PS4 updates from Firmware A to Firmware B, Firmware A is kept as a backup in the secondary slot. If you own a newer PS4 Slim or Pro, no downgrade to 1
But the readme file in the preview was specific. It didn't promise a full custom firmware (CFW). It promised a "soft bridge." It claimed to utilize a vulnerability in the PS4's Rest Mode resume protocol to inject a temporary spoof, tricking the system into thinking it was running an older kernel version just long enough to launch a payload.
Anyone claiming to have cracked the private encryption keys used by Sony to sign PS4 firmware updates. These keys remain entirely secure. The Risks of Running Untrusted Software Tools that claim to downgrade your PS4 by
“PS4 Tool Downgrade v1.00” is almost certainly for modern PS4 firmware versions. Any download claiming otherwise should be treated as potentially dangerous (brick risk or malware). Users interested in PS4 modding should instead check reputable, up-to-date sources for their specific firmware version and understand the permanent hardware and account risks.
RewindPS4 acts as a local network proxy. By intercepting the download request, it tricks your console into retrieving an older game version (like v1.00 ) from Sony's own servers instead of the latest patch.