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GPT-5.5

GPT-5.5

Frontier Vision OpenAI

OpenAI's newest frontier model for the most complex professional work. Features 1.05M context window, 128k output tokens, and reasoning token support. Reasoning.effort supports: none, low, medium (default), high and xhigh.

Try on Simtheory
Qwen 3.6 Plus Frontier Claude 4.5 Sonnet Frontier Claude 4.5 Sonnet (thinking) Frontier Claude 4.6 Opus Frontier Claude 4.6 Opus Max Frontier Claude 4.6 Sonnet Frontier Claude 4.6 Sonnet Max Frontier Claude 4.7 Opus Frontier Claude 4.7 Opus Max Frontier Claude Fable 5 Frontier

Specifications

Context window 1,050,000 tokens
Max output 128,000 tokens
Knowledge cutoff December 2025
Multipart messages Yes
Vision capabilities Yes

Default Parameters

Temperature 0.3
Top P 1.0
Frequency penalty 0.0
Presence penalty 0.0

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