OpenAI

GPT-5.5 System Card

Brief

GPT-5.5 is a model released by OpenAI on 2026-04-23 for complex real-world tasks (coding, research, spreadsheets), designed to ask for less guidance, use tools better, and self-check. OpenAI ran predeployment safety evaluations, Preparedness Framework assessments and targeted red-teaming (cybersecurity, biology), collected feedback from nearly 200 early-access partners, and updated deployment safeguards on 2026-04-24.

Why it matters

OpenAI published the GPT-5.5 system card on 2026-04-23 and updated it on 2026-04-24 to add API deployment safeguard details; the post is on the OpenAI Blog and the author is listed as unknown.

Key details

  • GPT-5.5 is designed for complex real-world work (coding, online research, document and spreadsheet creation, cross-tool workflows), aims to ask for less guidance and self-check more, and OpenAI treats GPT-5.5 results as strong proxies for GPT-5.5 Pro — which uses a parallel test-time compute setting and is evaluated separately when relevant.
  • Predeployment safety: GPT-5.5 underwent the full suite of safety evaluations and OpenAI’s Preparedness Framework, including targeted red-teaming for advanced cybersecurity and biology capabilities, and received feedback from nearly 200 early-access partners; OpenAI says it ships GPT-5.5 with its strongest safeguards to date and ran most evaluations offline.
Source evidence

GPT‑5.5 is a new model designed for complex, real-world work, including writing code, researching online, analyzing information, creating documents and spreadsheets, and moving across tools to get things done. Relative to earlier models, GPT‑5.5 understands the task earlier, asks for less guidance, uses tools more effectively, checks it work and keeps going until it’s done.

We subjected the model to our full suite of predeployment safety evaluations and our Preparedness Framework, including targeted red-teaming for advanced cybersecurity and biology capabilities, and collected feedback on real use cases from nearly 200 early-access partners before release. We are releasing GPT‑5.5 with our strongest set of safeguards to date, designed to reduce misuse while preserving legitimate, beneficial uses of advanced capabilities.

We generally treat GPT‑5.5’s safety results as strong proxies for GPT‑5.5 Pro, which is the same underlying model using a setting that makes use of parallel test time compute. As noted below, we separately evaluate GPT‑5.5 Pro in certain cases because we judge that the setting could materially impact the relevant risks or appropriate safeguards posture. Except where noted, the results in system cards describe evaluations we ran in an offline setting.

This card was updated on April 24, 2026, to include additional information about safeguards for the deployment of GPT‑5.5 and GPT‑5.5 Pro in the API.

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