What is your ? (e.g., running homebrew, fixing a broken system) Do you have any experience with hardware soldering ?

, but only goes back one firmware version and requires expert soldering. Best Path for Homebrew

Be extremely cautious of any website claiming you can downgrade by simply downloading a file to a USB drive or entering a website on the PS4 browser.

If your console is on firmware 11.00, and your previous version was 10.50, you can revert to 10.50. You cannot jump from 11.00 down to a much older version like 9.00 using this method unless 9.00 was your immediate last firmware. 2. Physical Motherboard Swapping

The concept of a "PS4 Tool Downgrade v1.00 verified" software-only solution is frequently a subject of debate and misinformation within the console modding community. While hardware-based "reversion" techniques exist, there is no verified, public, software-only tool that can simply downgrade a PlayStation 4’s system firmware to any arbitrary version. The Technical Reality: Reversion vs. Downgrading