When was GPT-5.4 Cyber released?

GPT-5.4 Cyber was released by OpenAI on Tuesday, Apr 14 2026.

Who made GPT-5.4 Cyber?

GPT-5.4 Cyber was built by OpenAI. Creators of ChatGPT and the GPT series of models. Pioneered large-scale language model research.

Is GPT-5.4 Cyber open source?

No. GPT-5.4 Cyber is a closed model. The weights are not published — it is available only through the provider's own API, apps, or partner platforms.

What came before and after GPT-5.4 Cyber?

OpenAI's previous tracked release was GPT-5.4 nano on Mar 17 2026, 28 days earlier. It was followed by GPT-5.5 on Apr 23 2026.

GPT-5.4 Cyber

Released Apr 14 2026

GPT-5.4 Cyber is an AI model released by OpenAI on Tuesday, Apr 14 2026, 28 days after GPT-5.4 nano.

About

OpenAI announced GPT-5.4 Cyber on April 14, 2026, alongside an expansion of its Trusted Access for Cyber program. The model was trained to answer a wider range of requests from verified defenders.

Access depended on verification and the customer’s program tier. OpenAI retired the first-party API endpoint on October 1, 2026.

Frequently asked questions

: GPT-5.4 Cyber was released by OpenAI on Tuesday, Apr 14 2026.
: GPT-5.4 Cyber was built by OpenAI. Creators of ChatGPT and the GPT series of models. Pioneered large-scale language model research.
: No. GPT-5.4 Cyber is a closed model. The weights are not published — it is available only through the provider's own API, apps, or partner platforms.
: OpenAI's previous tracked release was GPT-5.4 nano on Mar 17 2026, 28 days earlier. It was followed by GPT-5.5 on Apr 23 2026.