GPT-5.5

Released April 23, 2026 under the internal codename 'Spud', GPT-5.5 was the first OpenAI model fully retrained from scratch since GPT-4.5, replacing the incremental GPT-5.x variants. It shipped with a natively omnimodal architecture that processes text, images, audio, and video through a single unified model, and became the first OpenAI API model with a one-million-token context window as standard.

At launch it set new benchmark records for the company: 88.7% on SWE-bench Verified and 82.7% on Terminal-Bench 2.0. A June 2026 variant, GPT-5.5-Cyber, powers OpenAI's 'Patch the Planet' initiative for autonomous vulnerability patching in open-source projects. OpenAI retired GPT-5.5 from ChatGPT, ChatGPT Work, and Codex on October 14, 2026, though it remains available through the API — so developers with hardcoded model names should migrate to GPT-5.6 Sol or GPT-6 Astra.