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OpenAI: GPT-5.1-Codex-Max

openai/gpt-5.1-codex-max

ReasoningToolsJSONVision
Use via OpenRouter ↗
Intelligence
Design Elo
Speed
97
65th fastest
Latency
2.5s
first token
Input price
$1.25
221st cheapest
Context
400K
128K max out

How it compares

Faster than79%
of all ranked models
Cheaper than26%
of all ranked models

Overview

GPT-5.1-Codex-Max is OpenAI’s latest agentic coding model, designed for long-running, high-context software development tasks. It is based on an updated version of the 5.1 reasoning stack and trained on agentic...

Providers & pricing (2)

ProviderIn $/MOut $/MUptime
OpenAIcache$1.25$10.00100%
Azurecache$1.25$10.00

Specifications

Context window400K
Max output128K
Knowledge cutoff
Input modalitiestext, image
Output modalitiestext
Prompt cachingSupported
Cache read price$0.125/M
ModeratedYes

GPT-5.1-Codex-Max FAQ

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

GPT-5.1-Codex-Max costs $1.25 per million input tokens and $10.00 per million output tokens via OpenRouter, making it 221st cheapest of 298 paid models.

How fast is GPT-5.1-Codex-Max?

GPT-5.1-Codex-Max generates around 97 tokens per second with 2.5s time-to-first-token (p50), the 65th fastest tracked model.

What is GPT-5.1-Codex-Max's context window?

GPT-5.1-Codex-Max supports a 400K-token context window and can output up to 128K tokens. It accepts text, image input.

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