GPT-5.1 Instant and GPT-5.1 Thinking System Card Addendum

GPT-5.1 Instant and GPT-5.1 Thinking System Card Addendum | OpenAI

November 12, 2025

GPT‑5.1 Instant and GPT‑5.1 Thinking System Card Addendum

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Introduction

As described in our blog⁠, GPT‑5.1 Instant and GPT‑5.1 Thinking are the next iteration of our GPT‑5 models. GPT‑5.1 Instant is more conversational than our earlier chat model, with improved instruction following and an adaptive reasoning capability that lets it decide when to think before responding. GPT‑5.1 Thinking adapts thinking time more precisely to each question. GPT‑5.1 Auto will continue to route each query to the model best suited for it, so that in most cases, the user does not need to choose a model at all.

The comprehensive safety mitigations for these models are largely the same as we described in the GPT‑5 System Card⁠. This system card addendum provides updated baseline safety metrics for these new model versions. As we noted in our recent GPT‑5 system card addendum on sensitive conversations⁠, we have expanded the baseline safety evaluations that we conduct as part of pre-deployment safety review to include evaluations for mental health (covering situations where there are signs that a user may be experiencing isolated delusions, psychosis, or mania) and for emotional reliance (covering output related to unhealthy emotional dependence or attachment to ChatGPT).

In this card we also refer to GPT‑5.1 Instant as gpt-5.1-instant, and GPT‑5.1 Thinking as gpt-5.1-thinking.

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OpenAI

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