There is a legitimate technique called Firmware Revert , but it requires advanced micro-soldering skills and specific hardware.
: Any site asking you to download a "13.02 to 9.00 Downgrade.pup" file is dangerous and could contain malware. ps4 downgrade 1302 to 900
: Initializing your PS4 from the Safe Mode menu will wipe your data, but it will not lower your firmware version. Hardware Revert: The Only Semi-Solution There is a legitimate technique called Firmware Revert
Modern consoles use "fuses" (often called eFuses) that are "blown" during an update. Once a higher firmware is installed, the console's hardware will refuse to boot any older version stored on the hard drive or a USB. ps4 downgrade 1302 to 900