GPT-5.3-Codex
GPT-5.3 Instant Launches with Fewer Refusals, Lower Hallucination Rates, and Improved Web Search
OpenAI released GPT-5.3 Instant on February 12, 2026, reducing hallucination rates by up to 26.8% and cutting unnecessary refusals across ChatGPT conversations.
OpenAI Unveils GPT-5.3-Codex: The Most Advanced Agentic Coding Model That Helped Build Itself
OpenAI launches GPT-5.3-Codex, the most advanced agentic coding model that participated in its own development, achieving breakthrough performance across software engineering and professional knowledge work benchmarks.