OpenAI: GPT-5.6 Terra Pro

OpenAI: GPT-5.6 Terra Pro is a large language model from OpenAI. It costs $2.00 per million input tokens and $12.00 per million output tokens. Its context window is 1.1M tokens.

ReasoningTool callingStructured outputPrompt cachingBatch tierfile inputimage input

Input / 1M tokens: $2.00
Output / 1M tokens: $12.00
Cached input / 1M: $0.200
Context window: 1.1M

This model also charges $0.01 per search request

That is $10.00 per 1,000 requests, billed on top of the token prices above. On a typical 1,000-in / 500-out exchange the tokens cost $0.008, so the search fee is 1.3× the token cost. Per-token rankings elsewhere ignore this entirely.

Who serves it cheapest

2 hosts serve GPT-5.6 Terra Pro. Same weights, same API - the price difference is pure margin and routing.

Providers serving OpenAI: GPT-5.6 Terra Pro, cheapest first
Provider	Input / 1M	Output / 1M	Context	Throughput	Uptime 24h
OpenAICheapest	$1.00	$6.00	1.1M	-	-
Azure	$2.00	$12.00	1.1M	-	99.9%

The spread between OpenAI and Azure is 2.0× for identical weights. Quantization and context limits differ, so check both columns before switching.

About GPT-5.6 Terra Pro

GPT-5.6 Terra Pro is the same underlying model as [GPT-5.6 Terra](https://openrouter.ai/openai/gpt-5.6-terra), served with `reasoning.mode` set to `pro` for higher-quality responses on complex tasks. Learn more in OpenAI's docs: https://developers.openai.com/api/docs/guides/reasoning#reasoning-mode

Specifications

OpenAI: GPT-5.6 Terra Pro specifications
Model ID	`openai/gpt-5.6-terra-pro`
Provider	OpenAI
Context window	1.1M tokens
Max output	128K tokens
Input modalities	file, image, text
Output modalities	text
Knowledge cutoff	2026-02-16
Open weights	No
Released	July 9, 2026

Cheaper alternatives

Models that cost less than GPT-5.6 Terra Pro while keeping at least half its context window and every input modality it supports.

GPT-5.6 Sol Pro

$2.00 in · $10.00 out

1.1× cheaper

GPT-5.6 Sol

$2.00 in · $10.00 out

1.1× cheaper

Claude Sonnet 5

$2.00 in · $10.00 out

1.1× cheaper

GPT-4.1

$2.00 in · $8.00 out

1.3× cheaper

Gemini 2.5 Pro

$1.25 in · $10.00 out

1.3× cheaper

Frequently asked

How much does OpenAI: GPT-5.6 Terra Pro cost?

$2.00 per million input tokens and $12.00 per million output tokens. Cached input reads cost $0.200 per million tokens.

What is the context window of OpenAI: GPT-5.6 Terra Pro?

1.1M tokens, with up to 128K tokens of output per request.

Does OpenAI: GPT-5.6 Terra Pro have extra fees beyond per-token pricing?

Yes. OpenAI: GPT-5.6 Terra Pro charges $0.01 per search request - $10.00 per 1,000 requests - on top of $2.00 per million input tokens and $12.00 per million output tokens. On a typical 1,000-input / 500-output exchange the search fee alone is 1.3× the token cost.

Which provider serves OpenAI: GPT-5.6 Terra Pro cheapest?

OpenAI at $1.00 per million input tokens - 2.0× cheaper than Azure, the most expensive of the 2 hosts serving it.

Confirm against the source: OpenAI official pricing.