OpenAI
OpenAI: GPT-5.5 Pro
openai/gpt-5.5-pro
GPT-5.5 Pro is OpenAI’s high-capability model optimized for deep reasoning and accuracy on complex, high-stakes workloads. It features a 1M+ token context window (922K input, 128K output) with support for text and image inputs, and is designed for long-horizon problem solving, agentic coding, and precise execution across multi-step workflows.
Input
$30
/ 1M tokens
Output
$180
/ 1M tokens
Context window
1.05M
tokens
Limits
Context
1,050,000
tokens
Max output
128,000
12% of the context window
Model facts
Author
OpenAI
Tokenizer
GPT
Modality
Text + Image + File -> Text
Knowledge cutoff
2025-12-01
Created
Apr 24, 2026
Reasoning
RequiredDefault MediumXhighHighMedium
Publication status
Hugging Face: unavailableLicense: not publishedParameter count: not published
Modalities
Input · FileInput · ImageInput · TextOutput · Text
Generation controls
Include reasoningMax tokensReasoningReasoning effortResponse formatSeedStructured outputsTool choiceToolsVerbosity