GPT-5.1 Codex Max API Pricing

GPT-5.1 Codex Max pricing by provider

5 listings across 3 providers. Token prices are in US dollars per 1M tokens. The highlighted row is the price quoted above.

What GPT-5.1 Codex Max costs in practice

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

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

GPT-5.1 Codex Max features

Input: text, image. Output: text.

• Function calling
• Parallel tool calls
• Structured output
• Image input
• PDF input
• Reasoning
• Prompt caching
• Web search

Use GPT-5.1 Codex Max with LiteLLM

Call GPT-5.1 Codex Max through the LiteLLM Python SDK, or put it behind the LiteLLM proxy and send OpenAI-format requests to /v1/responses. LiteLLM tracks the cost of every request at these prices.

from litellm import completion

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

model_list:
  - model_name: gpt-5.1-codex-max
    litellm_params:
      model: gpt-5.1-codex-max
      api_key: os.environ/OPENAI_API_KEY

curl http://0.0.0.0:4000/v1/chat/completions \
  -H "Content-Type: application/json" \
  -H "Authorization: Bearer sk-1234" \
  -d '{
    "model": "gpt-5.1-codex-max",
    "messages": [{"role": "user", "content": "Hello!"}]
  }'

GPT-5.1 Codex Max FAQ

More OpenAI models

• GPT-5.5 Pro$30 / $180 per 1M tokens
• GPT-5.3 Codex Spark
• GPT-5.3 Instant
• GPT-5.4 Pro$30 / $180 per 1M tokens
• GPT-5.3 Codex$1.75 / $14 per 1M tokens
• GPT-5.2 Codex$1.75 / $14 per 1M tokens
• GPT-5.2 Pro$21 / $168 per 1M tokens
• GPT-5.1 Codex$1.25 / $10 per 1M tokens