OpenAI Just Released GPT-5.5. Here's What It Actually Does (and What It Costs You)

GPT-5.4 shipped on March 5. Seven weeks later, on April 23, 2026, OpenAI released GPT-5.5 — and the pace alone tells you something about where this race is headed. This isn't iteration for iteration's sake. GPT-5.5 is a genuinely different model from the ground up, and if you're building on top of OpenAI's stack, the changes matter in ways that go beyond the benchmark table. Here's everything developers need to know. The Problem It's Solving The core complaint with every prior GPT-5.x model was