OpenAI Releases GPT-5.5 Instant System Card
OpenAI published the system card for GPT-5.5 Instant, its latest instant model, on April 29, 2026. The safety approach mirrors previous models, but GPT-5.5 Instant is the first instant model classified as High capability in Cybersecurity and Biological & Chemical Preparedness, with appropriate safeguards. The model is also referred to as gpt-5.5-instant; there is no GPT-5.4 Instant, and the baseline is GPT-5.3 Instant. To avoid confusion, GPT-5.5 is called GPT-5.5 Thinking. The card details safety mitigations implemented as of April 23 and April 28, 2026.
Key facts
- GPT-5.5 Instant is OpenAI's latest instant model.
- System card published April 29, 2026.
- First instant model treated as High capability in Cybersecurity and Biological & Chemical Preparedness.
- Safety mitigations similar to previous models.
- Model also called gpt-5.5-instant.
- No GPT-5.4 Instant exists; baseline is GPT-5.3 Instant.
- GPT-5.5 is referred to as GPT-5.5 Thinking.
- Safety updates from April 23 and April 28, 2026.
Entities
Institutions
- OpenAI