GPT 5.5 Pro
GPT 5.5 Pro is a text generation model from OpenAI with a 1,000,000-token context window and reasoning capabilities.
OpenAILarge-context reasoning from OpenAI
GPT 5.5 Pro is a large language model developed by OpenAI, released in April 2026. It is designed for text generation tasks and features a context window of 1,000,000 tokens, allowing it to process and reason over very long documents or conversation histories in a single pass. The model supports a maximum response size of 128,000 tokens and is tagged as a reasoning-focused model.
GPT 5.5 Pro is well suited for tasks that require sustained attention across large bodies of text, such as analyzing lengthy documents, multi-turn conversations, or complex reasoning chains. Its large context capacity makes it a practical choice for workflows where retaining information across many pages or exchanges is essential. The model is available directly through MindStudio without requiring separate API key configuration.
What GPT 5.5 Pro supports
Extended Context Window
Processes up to 1,000,000 tokens in a single request, enabling analysis of very long documents or extended conversation histories without truncation.
Reasoning
Applies structured reasoning to complex prompts, supporting multi-step problem solving and logical inference across long inputs.
Long-Form Text Generation
Generates responses of up to 128,000 tokens, making it suitable for drafting detailed reports, summaries, or extended written content.
Latest Model Version
Represents OpenAI's most recently released model in the GPT line as of April 2026, incorporating the latest training and alignment updates.
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Get Started FreeCommon questions about GPT 5.5 Pro
What is the context window size for GPT 5.5 Pro?
GPT 5.5 Pro has a context window of 1,000,000 tokens, meaning it can process up to one million tokens of input in a single request.
What is the maximum response length?
The model supports a maximum response size of 128,000 tokens per output.
When was GPT 5.5 Pro released?
GPT 5.5 Pro was released in April 2026 by OpenAI.
What types of inputs does GPT 5.5 Pro accept?
Based on the available metadata, GPT 5.5 Pro is a text generation model. Image and video analysis support is not confirmed in the current metadata.
Is pricing information available for GPT 5.5 Pro?
Published pricing for GPT 5.5 Pro is not listed in the current metadata. Check OpenAI's official pricing page or MindStudio's platform for the latest cost details.
Parameters & options
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