GPT 5.4 Pro Is the STRONGEST AI Model I’ve Tested (But Costs a TON)

GPT 5.4 Pro is being positioned as the strongest “agentic” AI model tested so far—capable of building and modifying real, playable software artifacts end-to-end—but it comes with a steep price tag that makes it a tool for only the hardest jobs. In hands-on demos, GPT 5.4 Pro repeatedly generated complex 3D/interactive outputs by writing code, running multi-step tasks, and iterating until the result works—most notably when it autonomously edited a Pokémon Red ROM to swap in AI “starter” characters and even produced a functioning Minecraft-like world from scratch.

The most striking proof of autonomy came from a Pokémon Red ROM modification performed by GPT 5.4. The game booted normally, followed the usual start flow, and presented modded content directly in gameplay—down to selecting starters and battling with moves that reflected the chosen AI persona. The workflow wasn’t just text generation; it involved editing a real ROM and producing a playable artifact that launched like a standard game.

Other demos reinforced the same theme: long, careful “thinking” paired with coding and agentic execution. A Minecraft clone attempt produced a procedural world with multiple block types, a house, and environmental cues like a setting sun, nighttime, and clouds. A separate front-end comparison showed that enabling “skills” changed the look and usability tradeoffs: without skills, the interface was more visually bold, while with skills it became more structured and easier to parse at a glance.

Where GPT 5.4 Pro’s strengths showed most clearly was in difficult technical tasks that required both accuracy and interactive behavior. In a 3D engine visualization prompt (including X-ray views of pistons and the ability to start/rev/stop), GPT 5.4 initially failed to render the engine in one standard configuration, while Gemini 3.1 Pro succeeded on the first try. But after “anti-gravity” bug-fixing, GPT 5.4 Pro produced a far more detailed engine model—complete with moving pistons, throttle behavior, exhaust heat/glow, and an educational mode showing gas flow—though it still had some positioning errors (e.g., incorrect valve placement).

GPT 5.4 Pro also delivered a “production-ready” instrument pack: it recreated 18 classic band instruments using code and agentic research, then packaged the output into a ~60 MB zip with spectrogram visualizations and playable audio. The build time was about 65 minutes and 18 seconds, and the model was described as consistently willing to spend over an hour on complex tasks.

In broader comparisons, Gemini 3.1 Pro and Claude Opus 4.6 remained strong competitors—especially for efficiency and certain multimodal tasks. A multimodality test using a distorted Family Guy image showed GPT 5.4 “thinking” misidentifying characters (Batman/Snoopy instead of Peter Griffin/Brian), while Gemini handled it better. For 3D water simulation on a rotatable globe with lemon-tree spawning, all three models worked on first try, but Claude’s variant was judged to have the most convincing physics detail, with GPT 5.4 Pro close behind.

The overall takeaway: GPT 5.4 Pro is “undefeated” for the most demanding, code-heavy, agentic work, but its API cost is described as astronomically higher than other options. The practical recommendation was to use GPT 5.4 Pro when the task is too complex for faster or cheaper models, while leaning on Gemini or Claude for multimodal speed/quality and on open-source alternatives (notably Qwen 3.5) for local use and cost control.