OpenAI: GPT-5.1-Codex pricing
GPT-5.1-Codex is a specialized version of GPT-5.1 optimized for software engineering and coding workflows. It is designed for both interactive development sessions and long, independent execution of complex engineering… OpenAI: GPT-5.1-Codex from OpenRouter costs $1.25 per 1M input tokens and $10.00 per 1M output tokens. Cached input is $0.130 per 1M. Context window 400,000 tokens.
API id openai/gpt-5.1-codex · OpenRouter · source · updated 2026-09-25 · general-purpose
$1.25
Input / 1M tokens
$10.00
Output / 1M tokens
$0.130
Cached input / 1M
400K
Context window
OpenAI: GPT-5.1-Codex specifications
- Provider
- OpenRouter
- API id
openai/gpt-5.1-codex- Model type
- general-purpose
- Context window
- 400K tokens
- Max output
- 128K tokens
- Currency
- USD
- Price source
- Provider API
- Last checked
- 2026-09-25
Tags
- flagship
- vision
What OpenAI: GPT-5.1-Codex costs in practice
| 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 cost per 1M tokens?
- OpenAI: GPT-5.1-Codex costs $1.25 per 1M input tokens and $10.00 per 1M output tokens on the standard tier. Cached input is $0.130 per 1M.
- What is OpenAI: GPT-5.1-Codex's context window?
- OpenAI: GPT-5.1-Codex 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?
- Yes. OpenAI: GPT-3.5 Turbo is $0.500 per 1M input tokens versus $1.25 for OpenAI: GPT-5.1-Codex, with a 16,385 token context window.
- Where does this OpenAI: GPT-5.1-Codex 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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