GPT-5.6 Terra Pro is described as OpenAI's higher-effort reasoning configuration of GPT-5.6 Terra, using the same underlying model with reasoning mode set to pro for higher-quality responses on complex tasks.
OpenAI’s documentation also says pro mode can improve reliability on difficult tasks and is enabled by keeping the selected GPT-5.6 model while setting the reasoning mode to pro.
| Developer | Open AI |
|---|---|
| Model ID | openai/gpt-5.6-terra-pro |
| Release Date | July 8, 2026 |
| Context Window | 1,050,000 tokens (~1.1M) |
| Max Output Tokens | 128,000 tokens |
| Modalities | Image, Text → Text |
| Capabilities | file input, parallel tool calls, reasoning, streaming, structured (JSON schema) output, tool/function calling, vision |
Same underlying model
GPT-5.6 Terra Pro is described as the same underlying model as GPT-5.6 Terra, with pro reasoning mode applied.
Higher-quality responses
The model is positioned for higher-quality responses on complex tasks.
Pro mode behavior
OpenAI says pro mode performs more model work to improve reliability on difficult tasks and returns a single final answer.
Execution mode, not a separate checkpoint
OpenAI guidance says pro mode is an execution mode applied to the selected GPT-5.6 model rather than a separate Pro model slug.
Complex tasks
Use it for difficult tasks where higher reliability matters.
Deep analysis
OpenAI recommends pro mode for deep analysis with clear evaluation criteria.
High-value coding or review
OpenAI guidance lists complex optimization and high-value coding or review as suitable uses for pro mode.
Longer-running workflows
OpenAI’s GPT-5.6 preview materials describe Pro variants as aimed at difficult tasks and longer-running workflows.
GPT-5.6 Terra
OpenAI describes GPT-5.6 Terra as the base model that Terra Pro uses with pro reasoning mode.
GPT-5.6 Sol Pro
OpenAI’s help center describes Sol Pro as the highest-capability GPT-5.6 option for difficult tasks and longer-running workflows.
Sources: https://openai.com/index/gpt-5-6/ · https://openrouter.ai/openai/gpt-5.6-terra-pro · https://developer.puter.com/ai/openai/gpt-5.6-terra-pro/
Measured on the AI/ML API gateway across live traffic. Figures are medians unless stated. Last updated 2026-10-12.
Long-document analysis and document review are documented as fit areas for GPT-5.6 Terra Pro, including parsing handwritten memos and performing extraction for later analysis.
High-volume business tasks are another stated use case, with examples such as customer support, internal tools, and document analysis.
Multimodal agentic workflows are also described, combining vision, web search, and tool calling for production work.
Deeper reasoning on complex tasks is a further documented fit, especially where improved accuracy and solution quality matter more than speed or cost.
import requests r = requests.post( "https://api.aimlapi.com/v1/chat/completions", headers={"Authorization": "Bearer " + AIMLAPI_KEY}, json={ "model": "openai/gpt-5.6-terra-pro", "messages": [ { "role": "user", "content": "Hello!" } ] }, ) print(r.json())
const r = await fetch("https://api.aimlapi.com/v1/chat/completions", { method: "POST", headers: { Authorization: `Bearer ${process.env.AIMLAPI_KEY}`, "Content-Type": "application/json", }, body: JSON.stringify({ "model": "openai/gpt-5.6-terra-pro", "messages": [ { "role": "user", "content": "Hello!" } ] }), }); console.log(await r.json());
curl -X POST https://api.aimlapi.com/v1/chat/completions \ -H "Authorization: Bearer $AIMLAPI_KEY" \ -H "Content-Type: application/json" \ -d '{"model":"openai/gpt-5.6-terra-pro","messages":[{"role":"user","content":"Hello!"}]}'
OpenAI-compatible — swap the base URL and it works with your existing SDK.
| Type | Price |
|---|---|
| Input | |
| Output | |
| Cached input |
Prompts with more than 272K input tokens are billed at 2x input and 1.5x output for the full request, and cache writes are billed at 1.25x the uncached input token rate.
| Benchmark | Score | What it measures | Source | Retrieved |
|---|---|---|---|---|
| GPQA Diamond | 92.9% | Google-proof graduate science questions (hardest subset) | Source | September 21, 2026 |
| Humanity's Last Exam | 22.8% | Expert-level questions across many domains | Source | September 21, 2026 |
| MMMU | 83.2% | College-level multimodal understanding + reasoning | Source | September 21, 2026 |
| AIME 2025 | 44.7% | Competition mathematics (AIME), 2025 | Source | September 21, 2026 |
| MMLU-Pro | 90.0% | Multi-discipline knowledge + reasoning (harder MMLU) | Source | September 21, 2026 |
| Model | Input | Output | Context | Best for |
|---|---|---|---|---|
GPT-5.6 Terra Pro This page | Agentic workflows and structured output |
GPT-5.6 Terra Pro has a 1,050,000 tokens context window and can return up to 128,000 tokens.
GPT-5.6 Terra Pro takes image, text as input and returns text.
Use openai/gpt-5.6-terra-pro as the model id. Requests go to https://api.aimlapi.com/v1/chat/completions.
GPT-5.6 Terra Pro became available on July 9, 2026.
GPT-5.6 Terra Pro is priced at input $2.7508 / 1M tokens, output $16.5048 / 1M tokens, cached input $0.27508 / 1M tokens.
Yes, GPT-5.6 Terra Pro can stream responses as they are generated.
Yes, GPT-5.6 Terra Pro accepts image input alongside text.
GPT-5.6 Terra Pro was built by OpenAI.
