Question 1

What is GPT-5.4 Pro?

Accepted Answer

GPT-5.4 Pro is a model from OpenAI, released on Mar 5, 2026. GPT-5.4 Pro is OpenAI's most advanced model, building on GPT-5.4's unified architecture with enhanced reasoning capabilities for complex, high-stakes tasks. It features a 1M+ token context window (922K input, 128K output) with support for text and image inputs. Optimized for step-by-step reasoning, instruction following, and accuracy, GPT-5.4 Pro excels at agentic coding, long-context workflows, and multi-step problem solving.

Question 2

How much does GPT-5.4 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-5.4 Pro on Respan?

Accepted Answer

4 providers serve GPT-5.4 Pro: Azure OpenAI, OpenAI, and OpenRouter. Azure OpenAI requires your own provider API key (BYOK).

Question 4

What is GPT-5.4 Pro's context window?

Accepted Answer

GPT-5.4 Pro accepts up to 1.1M tokens of context on its largest provider route.

Question 5

How do I use GPT-5.4 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-5.4-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-5.4 Pro?

Accepted Answer

Over the last 30 days of requests through the Respan gateway, the fastest provider was OpenAI at 3 tokens per second, and the lowest response latency was 3.7 seconds on OpenAI. Speed varies with request size and provider.

Question 7

Where does GPT-5.4 Pro rank on the Respan Index?

Accepted Answer

GPT-5.4 Pro scores 49.1 out of 100 on the Respan Index v1.1, ranking #25 of 138 models. By category: Coding 13.7, Agents 74.4, Reasoning 55.9, Knowledge & language 46.4, and Human preference 56.1 (estimated). The Respan Index combines independent and lab-reported benchmark results into one score, using benchmark data collected by llmmetric.com.

Question 8

How does GPT-5.4 Pro score on benchmarks?

Accepted Answer

GPT-5.4 Pro has 18 published benchmark scores, including WeirdML 57.4%, BrowseComp 89.3%, and GPQA Diamond 94.6%. Each score links to where it was published; the data is collected by llmmetric.com.

Provider	Context	Input	Output
Azure OpenAIBYOK only`azure/gpt-5.4-pro`	1.1M	$30.00/M	$180.00/M
OpenAI`openai/gpt-5.4-pro`	1.1M	$30.00/M	$180.00/M
OpenAI`openai/gpt-5.4-pro-2026-03-05`	1.1M	$30.00/M	$180.00/M
OpenRouter`openrouter/openai/gpt-5.4-pro`	1.1M	$30.00/M	$180.00/M

GPT-5.4 Pro

Providers

Certified where it counts.

Pricing

Cost by volume

Throughput and latency

Output speed

Response latency

Benchmarks

Respan Indexv1.1

Coding1

Agents2

Apps

GPT-5.4 Pro FAQ

Works with your entire stack

Built for AI agents.
Break less.
Ship more.

Reasoning7

Math6

Knowledge2