GPT-5.5

Releases

1. May 7

   GPT-5.5-Cyber

2. May 5

   GPT-5.5 Instant

Trends

• Frontier cyber capability ships to defenders behind gated access
• Agent benchmarks expose reliability gaps and lose trust
• Clinical AI evidence moves to peer-reviewed, physician-validated reasoning

Items

1. Jun 22

   OpenAI expands Daybreak with GPT-5.5-Cyber

   The full GPT-5.5-Cyber model (85.6% on CyberGym versus 81.8% for GPT-5.5) and an updated Codex Security plugin shift defenders from finding vulnerabilities to generating patches, launched with a 28-vendor partner program and the Trail of Bits-founded Patch the Planet initiative.

2. Jun 18

   GPT-5.5 Instant brings frontier health answers to ChatGPT

   The free model now matches OpenAI's Thinking models on HealthBench Professional and other evaluations built with 260+ physicians in 60 countries, improving urgent-care recognition and uncertainty handling for the 230M+ people asking ChatGPT health questions weekly.

3. May 11

   OpenAI's Daybreak cybersecurity platform

   Daybreak combines GPT-5.5-Cyber and Codex Security into a continuous vulnerability detection and remediation pipeline across three access tiers, with partners including Cisco, CrowdStrike, Palo Alto Networks, Cloudflare, and Zscaler, positioned against Anthropic's Project Glasswing.

4. May 5

   OpenAI's GPT-5.5 Instant

   The new ChatGPT default for all users makes 52.5% fewer hallucinated claims than GPT-5.3 Instant on high-stakes medical, legal, and financial prompts, and adds personalization from past chats, files, and Gmail with new memory sources showing which context shaped each answer.

5. May 7

   OpenAI's GPT-5.5-Cyber

   OpenAI scaled its Trusted Access for Cyber program to GPT-5.5 with a cybersecurity-specialized variant gated by identity verification, mirroring Anthropic's Project Glasswing model, and added a $10M Cybersecurity Grant Program in API credits for defensive research teams.

6. Apr 23

   OpenAI's GPT-5.5

   A fully retrained agentic model with a 1.05M-token context that sets a Terminal-Bench 2.0 record at 82.7% and scores 84.9% on GDPval and 39.6% on FrontierMath Tier 4, aimed at coding tasks with a median human effort of 20 hours; API access is pending.