# GPT-5.1 Codex API Pricing

As of October 10, 2026, GPT-5.1 Codex costs $1.25 per 1M input tokens and $10.00 per 1M output tokens on OpenAI, with cache reads at $0.125 per 1M tokens. It has a 400,000-token context window and returns up to 128,000 tokens per response.

- Page: https://models.litellm.ai/models/gpt-5.1-codex
- Lab: OpenAI
- LiteLLM model name: `gpt-5.1-codex`
- Context window: 400,000 tokens
- Max output: 128,000 tokens
- Added to LiteLLM: November 2025
- Deprecation date: July 23, 2026
- Prices updated: October 10, 2026

## Pricing by provider

Token prices in USD per 1M tokens.

| Provider | Model name | Input | Output | Cache read | Per image | Per second | Context |
|---|---|---|---|---|---|---|---|
| OpenAI | `gpt-5.1-codex` | $1.25 | $10.00 | $0.125 | – | – | 400K |
| Azure OpenAI | `azure/gpt-5.1-codex` | $1.25 | $10.00 | $0.125 | – | – | 272K |
| Azure OpenAI (snapshot 2025-11-13) | `azure/gpt-5.1-codex-2025-11-13` | $1.25 | $10.00 | $0.125 | – | – | 272K |
| Azure OpenAI (eu) | `azure/eu/gpt-5.1-codex` | $1.375 | $11.00 | $0.1375 | – | – | 272K |
| Azure OpenAI (global) | `azure/global/gpt-5.1-codex` | $1.25 | $10.00 | $0.125 | – | – | 272K |
| Azure OpenAI (us) | `azure/us/gpt-5.1-codex` | $1.375 | $11.00 | $0.1375 | – | – | 272K |

## Cost examples

1,000 requests with 2,000 input and 500 output tokens each:

- OpenAI: $7.50
- Azure OpenAI: $7.50

100 long-document requests with 100,000 input and 2,000 output tokens each:

- OpenAI: $14.50
- Azure OpenAI: $14.50

## Features

Supported: Function calling, Parallel tool calls, Structured output, Image input, PDF input, Reasoning, Prompt caching, Web search.

## Use it with LiteLLM

```python
from litellm import completion

response = completion(
    model="gpt-5.1-codex",
    messages=[{"role": "user", "content": "Hello!"}],
)
```

## FAQ

### How much does GPT-5.1 Codex cost?

GPT-5.1 Codex costs $1.25 per 1M input tokens and $10.00 per 1M output tokens on OpenAI, with cache reads at $0.125 per 1M tokens.

### What is the context window of GPT-5.1 Codex?

GPT-5.1 Codex has a 400,000-token context window and returns up to 128,000 tokens per response.

### Which providers offer GPT-5.1 Codex?

GPT-5.1 Codex is available from 2 providers through LiteLLM: OpenAI and Azure OpenAI.

### How do I call GPT-5.1 Codex with an OpenAI-compatible API?

Use the LiteLLM Python SDK with model="gpt-5.1-codex", or add the model to the LiteLLM proxy's config.yaml and send requests to /v1/responses from any OpenAI client. LiteLLM tracks the cost of every request at the prices on this page.

### What features does GPT-5.1 Codex support?

GPT-5.1 Codex supports function calling, parallel tool calls, structured output, image input, PDF input, reasoning, prompt caching and web search.

### When did LiteLLM add GPT-5.1 Codex?

GPT-5.1 Codex was added to LiteLLM's model price file in November 2025.

### Is GPT-5.1 Codex being deprecated?

OpenAI deprecated gpt-5.1-codex on July 23, 2026.

Source: LiteLLM model price file, https://github.com/BerriAI/litellm/blob/main/model_prices_and_context_window.json