There is one semi-legitimate method used by the homebrew community, but it is not a generic converter. It involves the official PS2 emulator hidden inside the PS4 (used for PS2 Classics).
Hackers discovered that by reverse-engineering the PS4's internal ps2_netemu.self emulator, they could force it to run some PS3 games? No. That was a myth. The real method is:
There is no known tool that takes God of War Ascension (PS3) and spits out a playable PS4 PKG. ps3 to ps4 pkg converter
To understand why a true converter is impossible, think of it like this:
A PS3 game is a novel written in Japanese (Cell architecture). A PS4 game is a novel written in Portuguese (x86). A "converter" would have to translate not just the words, but the entire grammar, sentence structure, and cultural context – instantly, without errors, and in real-time. There is one semi-legitimate method used by the
A converter implies static translation. But PS3 code relies on six synergistic processing elements (SPEs) that work in parallel. The PS4 has no equivalent. The only way to run that code is through dynamic recompilation (Dynarec) – which is emulation. Emulation is not conversion.
The closest real-world parallel is the PS3 Classics Emulator that Sony built for the PS4 to run a handful of PS3 games (e.g., God of War HD remasters). That emulator is: There is no known tool that takes God
No public tool can inject your own PS3 PKG into Sony’s emulator wrapper.
Some developers have attempted to create tools that unpack a PS3 PKG, extract assets (textures, audio, models), and repackage them into a PS4 PKG with a wrapper. This is only feasible for very simple homebrew games or small indie titles that do not rely on complex Cell-specific instructions. No public tool exists for commercial games.
Before discussing conversion, we must understand what a .pkg file actually is on both consoles.