OpenAI: GPT-5.5 Pro

Reasoning Tool Calling Attachments

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...

Providers 1

Released Apr 24, 2026

Input Modalities text, image, pdf

Output Modalities text

Tarsk Use coding

Available Providers (1)

Provider	Model ID	Input Cost	Output Cost	Context	Max Output	Docs
Kilo Gateway	`openai/gpt-5.5-pro`	$30/MTok	$180/MTok	1.1M	128K

Capabilities

Reasoning

Tool Calling

Attachments

Open Weights

Structured Output