Azure

GPT-5.1 Codex Max — Benchmark Scores, Pricing & Performance Analysis

MID
Input Cost
$1.3/1M
Output Cost
$10.0/1M
Context Window
400K
Max Output
128K
Knowledge Cutoff
Sept 2024
Accepts
text, image

GPT-5.1 Codex Max is an AI model by Azure. View detailed benchmark scores, pricing data, and performance metrics on Serenities AI Models.

Specifications last checked against the provider on . Benchmark scores carry their own source, linked beside each number.

Cost Benchmarks

Output Cost
$10.0335th of 413

Cost per 1M output tokens

OpenRouter API
Input Cost
$1.3306th of 413

Cost per 1M input tokens

OpenRouter API
Cached Input Cost
$0.1369th of 136

Cost per 1M cached input tokens — the price that actually applies to a long agent conversation

OpenRouter API

Context Benchmarks

Context Length
400K90th of 451

Maximum context window size

OpenRouter API

Available from 13 providers

The same model costs different amounts depending on who serves it. You can bring your own key for 3 of these — connect it here.

ProviderInput / 1MOutput / 1MCached inContextYour key
Poe$1.1$9$0.11400K—
Jiekou.AI$1.125$9—400K—
Abacus$1.25$10—400K—
Azure$1.25$10$0.125400KSupported
DigitalOcean$1.25$10$0.125400K—
Eden AI$1.25$10$0.125272K—
Kilo Gateway$1.25$10$0.125400K—
Ofox$1.25$10$0.13256K—
OpenCode Zen$1.25$10$0.125400K—
OpenRouter$1.25$10$0.125400KSupported
Vercel AI Gateway$1.25$10$0.125400KSupported
Vivgrid$1.25$10$0.125400K—
NanoGPT$2.5$20$0.25400K—

GPT-5.1 Codex Max — Frequently Asked Questions

How much does GPT-5.1 Codex Max cost?

GPT-5.1 Codex Max costs $1.3 per 1M input tokens and $10.0 per 1M output tokens. This is mid-range pricing for its capability level.

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

GPT-5.1 Codex Max has a context window of 400K tokens. This determines how much text, conversation history, and code the model can process in a single request.

Who created GPT-5.1 Codex Max?

GPT-5.1 Codex Max was created by Azure. It is classified as a mid model in our catalogue.

Is GPT-5.1 Codex Max open source?

No, GPT-5.1 Codex Max is a proprietary model. It is available through Azure's API and compatible providers.