Question 1

What is GPT-5.5 Pro?

Accepted Answer

GPT-5.5 Pro is a model from OpenAI, released on Apr 23, 2026. 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.

Question 2

How much does GPT-5.5 Pro cost?

Accepted Answer

On the Respan gateway, input starts at $30.00 per 1M tokens on every provider, and output starts at $180.00 per 1M tokens on every provider, after gateway discounts.

Question 3

Which providers serve GPT-5.5 Pro on Respan?

Accepted Answer

3 providers serve GPT-5.5 Pro: OpenAI and OpenRouter.

Question 4

What is GPT-5.5 Pro's context window?

Accepted Answer

GPT-5.5 Pro accepts up to 1.1M tokens of context on its largest provider route.

Question 5

How do I use GPT-5.5 Pro with the Respan gateway?

Accepted Answer

Point any OpenAI-compatible SDK at https://api.respan.ai/api/ with your Respan API key and set the model to "openai/gpt-5.5-pro". To set it up with a coding agent, copy the agent setup prompt at the top of this page.

Question 6

How fast is GPT-5.5 Pro?

Accepted Answer

Over the last 30 days of requests through the Respan gateway, the fastest provider was OpenRouter at 5 tokens per second, and the lowest response latency was 4.1 seconds on OpenAI. Speed varies with request size and provider.

Question 7

How does GPT-5.5 Pro score on benchmarks?

Accepted Answer

GPT-5.5 Pro has 11 published benchmark scores, including BrowseComp 90.1%, SimpleBench 76.9%, and FrontierMath Tiers 1-3 v2 87.7%. Each score links to where it was published; the data is collected by llmmetric.com.

Provider	Context	Input	Output
OpenAI`openai/gpt-5.5-pro`	1.1M	$30.00/M	$180.00/M
OpenAI`openai/gpt-5.5-pro-2026-04-23`	1.1M	$30.00/M	$180.00/M
OpenRouter`openrouter/openai/gpt-5.5-pro`	1.1M	$30.00/M	$180.00/M

GPT-5.5 Pro

Providers

Certified where it counts.

Pricing

Cost by volume

Throughput and latency

Output speed

Response latency

Benchmarks

Agents2

Reasoning3

Math6

Apps

GPT-5.5 Pro FAQ

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