OpenAI just shipped another major update to its model lineup, and GPT-5.4 Thinking may be the most significant reasoning release since o1. Here's everything you need to know.
What Is GPT-5.4 Thinking?
GPT-5.4 Thinking is OpenAI's latest frontier model, built on the GPT-5 architecture with a dedicated extended-reasoning mode. When "thinking" is enabled, the model silently works through a problem — generating internal chain-of-thought steps before producing its final response. Users see a polished answer; under the hood, the model has stress-tested multiple solution paths.
This is distinct from the earlier o-series approach in one key way: GPT-5.4 Thinking seamlessly toggles between fast, direct responses and deep extended reasoning within a single conversation, dynamically allocating compute based on problem complexity.
Key Improvements Over Previous Models
- Reasoning depth: Sustained multi-step logic across 200+ reasoning steps with minimal drift
- Math and science: Near-perfect accuracy on AIME 2026 and GPQA-Diamond benchmarks — outperforming o3 on both
- Code generation: Produces working, well-structured code for complex algorithmic problems on the first attempt more often than any prior model
- Reduced over-thinking: A major criticism of early reasoning models was verbose, redundant chains. GPT-5.4 Thinking prunes unproductive paths much earlier
- Context window: 256k tokens — enough to reason over entire codebases or research papers in a single session
How It Compares to o3 and Claude
GPT-5.4 Thinking sits at the top of the OpenAI reasoning stack, above o3 Mini and standard GPT-5. On head-to-head benchmarks shared by independent researchers:
- vs. o3: GPT-5.4 Thinking wins on math, science, and multi-document reasoning; o3 Mini remains faster and cheaper for simpler tasks
- vs. Claude Sonnet 4.6: Comparable coding performance; Claude still shows advantages in long-form writing and instruction-following nuance
- vs. Gemini 2.5 Pro: Gemini retains its edge in multimodal tasks; GPT-5.4 Thinking leads on pure text reasoning
No single model dominates every category — the right choice still depends on your use case.
What This Means for AI Learners
For anyone building their AI skills, GPT-5.4 Thinking raises the bar in two ways. First, the tasks it handles reliably are expanding, meaning more of your work can be delegated to AI with confidence. Second, understanding how to direct a reasoning model effectively — knowing when to enable extended thinking, how to frame problems, and how to verify outputs — is becoming a core professional skill.
This is exactly the kind of capability gap that our AI Coach and courses are designed to help you close.
Getting Access
GPT-5.4 Thinking is rolling out to ChatGPT Plus, Team, and Enterprise subscribers, as well as via the OpenAI API. Pricing is higher than GPT-5 standard due to the additional compute used during reasoning, but OpenAI has introduced a "thinking budget" parameter that lets developers cap reasoning depth to control costs.
