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GPT-5.5
OpenAI · GPT-5
OpenAI released GPT-5.5 on April 24, 2026.
GPT-5.5 is the OpenAI frontier model for complex professional work released on April 24, 2026 to the Chat Completions and Responses APIs, with GPT-5.5 Pro in the Responses API for tougher problems that benefit from more compute. It reached Codex a day earlier. It supports a 1M token context window, image input, structured outputs, function calling, prompt caching, Batch, tool search, built-in computer use, hosted shell, apply patch, Skills, MCP and web search. Through mid-2026 OpenAI recommended GPT-5.5 for production API use over the chat-latest snapshots. Its successor is the GPT-5.6 family.
GPT-5.5 at a glance
- Released
- API model id
gpt-5.5gpt-5.5-pro- Available on
- OpenAI APICodex
- Previous model
- GPT-5.4 (March 5, 2026)
- Announcement
- developers.openai.com
What changed from GPT-5.4
Changes to plan for when moving from GPT-5.4: reasoning effort now defaults to medium, image_detail unset or auto uses the original behavior, and caching works only with extended prompt caching (in-memory prompt caching is not supported).
New to model names and version numbers? Read how AI labs version their models.
GPT-5.5 release timeline
The launch and every later OpenAI release that mentions GPT-5.5, oldest first.
- GPT-5.5 and GPT-5.5 Pro
Released GPT-5.5 , a new frontier model for complex professional work, to the Chat Completions and Responses API, and released GPT-5.5 Pro for Responses API requests for tougher problems that benefit from more compute. GPT-5.5 supports a 1M token context window, image input, str…
Source: OpenAI API Changelog
GPT-5.5 FAQ
When was GPT-5.5 released?
OpenAI released GPT-5.5 on April 24, 2026. The launch entry below links to the official announcement.
Where is GPT-5.5 available?
GPT-5.5 is available on OpenAI API and Codex. Later availability changes are listed under follow-up releases on this page.
What is the GPT-5.5 API model id?
Use gpt-5.5 and gpt-5.5-pro in OpenAI's API.
What came before GPT-5.5?
GPT-5.5 follows GPT-5.4, released on March 5, 2026.
Other OpenAI models
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