gpt-5-5

OpenAI released GPT-5.5 Instant as the new default ChatGPT model on May 5, 2026. The company claims the update produces 52.5% fewer hallucinations on high-stakes prompts and 37.3% fewer inaccurate claims on challenging conversations compared to GPT-5.3 Instant.

OpenAI will roll out GPT-5.5 Cyber only to 'critical cyber defenders' in the coming days, requiring an application process despite CEO Sam Altman previously criticizing Anthropic for taking the same approach with its competing cybersecurity tool Mythos.

Cline, the AI coding assistant, released v3.81.0 with support for GPT-5.5 for OpenAI Codex subscription users. The update also removes hardcoded welcome banners and adds enhanced memory diagnostics including heap snapshots for debugging out-of-memory issues.