LLM Reference

GPT-5.1 Codex Max

Released
2025-11-19
Last refreshed
2026-05-22
Status
Researched 45d ago
ProprietaryMultimodalCodingAgentsVisionJSON / Tool use

GPT-5.1 Codex Max is worth evaluating for coding, agents, and vision when its provider route and context window match the workload.

Use it for

  • Teams evaluating coding, agents, and vision
  • Buyers comparing 2 tracked provider routes

Do not use it for

  • Workloads where another current model has stronger sourced task evidence
Specifications
Family
GPT-5.1
Released
2025-11-19
Knowledge cutoff
2024-09
Specialization
code
Created by

Cutting-edge research and development.

San Francisco, California, United States
Founded 2015
Website
Pricing
Output / 1M
$10.00
Input / 1M
$1.25

Cheapest of 2 routes · OpenRouter

About

OpenAI's GPT-5.1-Codex-Max is a code-specialized model released November 19, 2025, optimized for agentic coding tasks including project-scale refactors, debugging, and multi-file edits. Uses context compaction to handle long-running tasks beyond a single context window. 30% more token-efficient than previous Codex on SWE-bench. Supports an extra-high reasoning effort option.

GPT-5.1 Codex Max is a proprietary model in the GPT-5.1 family. The structured metadata tracks multimodal input, reasoning, function calling, tool use, and structured outputs. This page tracks provider routes through OpenRouter and Vercel AI Gateway, with the cheapest tracked route listed at $1.25 input and $10 output per 1M tokens. No headline benchmark score is tracked for GPT-5.1 Codex Max yet.

Top use-case fit

Coding

Included by capability and metadata signals in the decision map.

Agents

Included by capability and metadata signals in the decision map.

Vision

Included by capability and metadata signals in the decision map.

Provider price ladder

Compare all 2
ProviderInput / 1MOutput / 1MCacheRoute
OpenRouter$1.25$10.00-
Serverless
Vercel AI Gateway$1.25$10.00read $0.125
Serverless

Capabilities

MultimodalReasoningFunction CallingTool UseStructured Outputs

Benchmark peer barsfor Coding

No task-mapped benchmark peers are available for this model yet.

Migration checks

No linked migration route is available for this model yet.

Rankings & picks(7)