What is GPT-5.5 and is it in ChatGPT and API?

What GPT-5.5 is

On April 23, 2026, OpenAI officially announced GPT-5.5.

The company positions it as a model focused on:

• multi-step coding
• agentic work
• computer use
• knowledge work such as research, spreadsheets, and documents

From a product perspective, GPT-5.5 is the next major step after GPT-5.4, with a clear emphasis on long-horizon task execution and stronger autonomy.

Official source:

• https://openai.com/index/introducing-gpt-5-5/

Where OpenAI says GPT-5.5 is stronger

According to OpenAI’s announcement, GPT-5.5 is especially aimed at:

• writing and debugging code
• researching information
• analyzing data
• creating documents and spreadsheets
• using tools to finish multi-step tasks

OpenAI also says GPT-5.5 keeps real-world serving latency close to GPT-5.4 while improving quality, especially in coding and knowledge work.

Is GPT-5.5 already in ChatGPT and the API

According to OpenAI:

• on April 23, 2026, GPT-5.5 started rolling out to Plus, Pro, Business, and Enterprise users in ChatGPT and Codex
• an April 24, 2026 update says GPT-5.5 and GPT-5.5 Pro became available in the API

So as of June 16, 2026, GPT-5.5 is no longer a limited preview. It is available across ChatGPT and the API based on OpenAI’s official announcement.

Who should care most about GPT-5.5

GPT-5.5 is especially relevant for:

• developers who want stronger coding performance
• teams building agent workflows
• people doing research or document-heavy work
• businesses that want AI to handle longer, messier tasks with less prompt micromanagement

For casual chat use, the difference may matter less than it does for technical or workflow-heavy use cases.

Conclusion

If you want the short version of OpenAI’s latest major model as of June 16, 2026, it is:

• GPT-5.5
• announced on April 23, 2026
• added to the API on April 24, 2026

This release is clearly positioned around practical AI work, especially coding, tool use, and multi-step task completion.