OpenAI GPT-5.4 Complete Guide: Benchmarks, Use Cases, Pricing, API, and GPT-5.4 Pro Comparison

OpenAI released GPT-5.4 on March 5, 2026 , and this is the first GPT release in a while that feels less like a narrow benchmark bump and more like a model-line reset. The reason is simple: GPT-5.4 is the first mainline OpenAI reasoning model that combines frontier professional-work quality, frontier coding from GPT-5.3-Codex, native computer use, and 1.05M-context API support in the same default model. That matters a lot if your real workload is not "one perfect answer in one shot," but messy multi-step work spread across documents, spreadsheets, web apps, codebases, and tool chains. The short answer: GPT-5.4 is now OpenAI's best all-around model for serious professional work. If you need one model that can research, write, analyze, code, use tools, drive browsers, and survive large contexts, this is the new default. If you need the highest ceiling and can tolerate much higher latency and price, GPT-5.4 Pro is the step-up. TL;DR GPT-5.4 launched on March 5, 2026 as OpenAI's new mainlin