How much does OpenAI: GPT-5.1-Codex-Max cost per 1M tokens?

OpenAI: GPT-5.1-Codex-Max costs $1.25 per 1M input tokens and $10.00 per 1M output tokens on the standard tier. Cached input is $0.125 per 1M.

What is OpenAI: GPT-5.1-Codex-Max's context window?

OpenAI: GPT-5.1-Codex-Max accepts up to 400,000 tokens in a single request, and can return up to 128,000 output tokens.

Is there a cheaper OpenRouter model than OpenAI: GPT-5.1-Codex-Max?

Yes. OpenAI: GPT-3.5 Turbo is $0.500 per 1M input tokens versus $1.25 for OpenAI: GPT-5.1-Codex-Max, with a 16,385 token context window.

Where does this OpenAI: GPT-5.1-Codex-Max price come from?

From the OpenRouter catalogue, because OpenRouter does not publish machine-readable pricing. OpenRouter is a reseller, so its rate can differ from OpenRouter's own — verify before committing spend.

OpenAI: GPT-5.1-Codex-Max pricing

GPT-5.1-Codex-Max is OpenAI’s latest agentic coding model, designed for long-running, high-context software development tasks. OpenAI: GPT-5.1-Codex-Max from OpenRouter costs $1.25 per 1M input tokens and $10.00 per 1M output tokens. Cached input is $0.125 per 1M. Context window 400,000 tokens.

API id openai/gpt-5.1-codex-max · OpenRouter · source · updated 2026-09-25 · general-purpose

$1.25

Input / 1M tokens

$10.00

Output / 1M tokens

$0.125

Cached input / 1M

400K

Context window

OpenAI: GPT-5.1-Codex-Max specifications

Provider: OpenRouter
API id: openai/gpt-5.1-codex-max
Model type: general-purpose
Context window: 400K tokens
Max output: 128K tokens
Currency: USD
Price source: Provider API
Last checked: 2026-09-25

What OpenAI: GPT-5.1-Codex-Max costs in practice

Estimated cost at common usage volumes
Workload	Input tokens	Output tokens	Estimated cost
Short chat turn	1,000	500	$0.0063
Document summary	50,000	2,000	$0.08
1M tokens in, 200K out	1,000,000	200,000	$3.25

Estimates use the standard tier and ignore caching discounts, so real bills with repeated prompt prefixes are typically lower.

Common questions

How much does OpenAI: GPT-5.1-Codex-Max cost per 1M tokens?: OpenAI: GPT-5.1-Codex-Max costs $1.25 per 1M input tokens and $10.00 per 1M output tokens on the standard tier. Cached input is $0.125 per 1M.
What is OpenAI: GPT-5.1-Codex-Max's context window?: OpenAI: GPT-5.1-Codex-Max accepts up to 400,000 tokens in a single request, and can return up to 128,000 output tokens.
Is there a cheaper OpenRouter model than OpenAI: GPT-5.1-Codex-Max?: Yes. OpenAI: GPT-3.5 Turbo is $0.500 per 1M input tokens versus $1.25 for OpenAI: GPT-5.1-Codex-Max, with a 16,385 token context window.
Where does this OpenAI: GPT-5.1-Codex-Max price come from?: From the OpenRouter catalogue, because OpenRouter does not publish machine-readable pricing. OpenRouter is a reseller, so its rate can differ from OpenRouter's own — verify before committing spend.

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OpenAI: GPT-5.1-Codex-Max specifications

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What OpenAI: GPT-5.1-Codex-Max costs in practice

Common questions

Head-to-head comparisons

Other OpenRouter models