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GPT-5.5 Pro

OpenAIProprietaryPending Human Review

GPT-5.5 Pro is the higher-compute GPT-5.5 tier for demanding research and professional questions. It launched in ChatGPT alongside GPT-5.5 before the API release. The tier aims for more accurate and comprehensive answers, using additional reasoning time and a higher token price. Its Responses API interface supports long-context, asynchronous work.

2026-04-23
Unreleased
Undisclosed proprietary architecture
Proprietary

Specifications

Parameters
Unreleased
Architecture
Undisclosed proprietary architecture
License
Proprietary
Context Window
1,050,000 tokens
Max Output
128,000 tokens
Training Data Cutoff
Dec 01, 2025
Type
multimodal
Modalities
textimage

Benchmark Scores

Advanced Specifications

Model Family
GPT-5
API Access
Available
Chat Interface
Not Available
Variants
gpt-5.5-pro-2026-04-23

Capabilities & Limitations

Capabilities
deep reasoningcodevisiontool use
Known Limitations
Can produce incorrect factual claims or code; important results require independent verification.Higher compute can increase response latency to several minutes.
Notable Use Cases
manuscript reviewdifficult researchprofessional analysis
Function Calling Support
Yes
Tool Use Support
Yes

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