// openai

GPT-5.1-Codex-Max

openai/gpt-5.1-codex-max

reasoningtool callingimage inputprompt caching
OpenRouter + LiveBenchAll modelsFull leaderboard

GPT-5.1-Codex-Max costs $1.25 per 1M input tokens and $10.00 per 1M output tokens with a 400K-token context window.

A reasoning, tool-calling model from openai, released Dec 4, 2025. LiveBench hasn't published a run for it, so this page carries measured price and specs only — no benchmark numbers.

Input / 1M
$1.25
Output / 1M
$10.00
Context
400K
LiveBench overall
Not evaluated

Specs and pricing

Input price

USD per 1M prompt tokens

$1.25
Output price

USD per 1M completion tokens, reasoning included

$10.00
Blended price

3:1 input:output — #64 most expensive of 343 listed models

$3.44
Cached input read

Blank means not priced separately — not free

$0.125
Cache write
Context window400,000 tokens
Max output128,000 tokens
Input modalitiestext, image
Tool callingYes
Extended reasoningYes
Knowledge cutoff
ListedDec 4, 2025
All OpenAI API pricing

What GPT-5.1-Codex-Max costs to run

Monthly list cost across five workload shapes, using the published cached-input rate where there is one. A floor, not a quote — batch discounts and cache writes aren't included.

WorkloadPer month
Support chatbot

1.2K in / 400 out × 200K requests

$1,019/mo
RAG assistant

8K in / 600 out × 100K requests

$1,150/mo
Coding agent

40K in / 4K out × 20K requests

$1,170/mo
Document extraction

20K in / 1.5K out × 50K requests

$1,944/mo
Bulk classification

500 in / 20 out × 5M requests

$3,563/mo
Price your own workload

Compare GPT-5.1-Codex-Max with

Benchmarked models at a similar price.

GPT-5.1-Codex-Max FAQ

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

GPT-5.1-Codex-Max lists at $1.25 per 1M input tokens and $10.00 per 1M output tokens, with cached input reads at $0.125 per 1M. A RAG assistant handling 100K requests a month (8K tokens in, 600 out) comes to about $1,150 at list price.

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

GPT-5.1-Codex-Max accepts up to 400,000 tokens of context and can return up to 128,000 output tokens per response.

Does GPT-5.1-Codex-Max support tool calling?

Yes — GPT-5.1-Codex-Max supports tool (function) calling and exposes extended reasoning. It accepts text, image input.

How does GPT-5.1-Codex-Max score on benchmarks?

LiveBench has not published a run for GPT-5.1-Codex-Max yet. Until it does, compare it on price and specs, or run your own evaluation on your own tasks.

What is the API model ID for GPT-5.1-Codex-Max?

On OpenRouter the model ID is "openai/gpt-5.1-codex-max". It was listed on Dec 4, 2025.

More from openai

How these numbers are produced

  • Price and specs — provider list data from OpenRouter, refreshed every 15 minutes. “Blended” is a 3:1 input:output mix.
  • Scores and ranksLiveBench release 2026-06-25. Ranks count only models that have a published run; a blank means “not evaluated”, never “bad”.
  • Cost per point — the measured dollars LiveBench spent on the run, divided by the score it earned.

Published benchmarks rank models on someone else's tasks. Before committing, see LLM & agent evaluation for building an eval on your own.