GPT-5.4 ships with a 1 million-token context window, native desktop and computer-use capabilities, and measurable benchmark gains across reasoning, coding, and agentic task completion. Tool calling gets an upgrade via toolsearch, and desktop navigation accuracy clears human baselines.
The reasoning engine is faster and more token-efficient than its predecessors. Real-world tests confirm strong coding output and long-form writing quality, but three failure modes persist: poor frontend aesthetic judgment, excessive verbosity, and premature task termination before full completion.
The full video is worth watching for the hands-on workflow tests, which reveal where the model actually breaks down under production conditions, not just where it scores well on paper. The gap between benchmark performance and reliable agentic behavior is exactly where the interesting detail lives.
[WATCH ON YOUTUBE →]