Question 1

What is GPT-5.1 Codex max?

Accepted Answer

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 workflows spanning software engineering, mathematics, and research.

Question 2

What is GPT-5.1 Codex?

Accepted Answer

What is GPT-5.1-Codex? GPT-5.1 Codex is a specialized version of GPT-5.1, built for long-running, agentic coding tasks rather than just snippet autocompletion. It is purpose-built for real software engineering and agentic workflows, which makes it the perfect engine behind our Issue-to-Plan automation workflow.

Question 3

What is the difference between GPT-5.1 and 5.1 Codex?

Accepted Answer

GPT-5.1 Codex is more restricted than previous model GPT-5 Codex I've tested both GPT‐5 Codex and GPT‐5.1 Codex in identical setups, and here's what I found: So yes, GPT‐5.1 Codex is practically more restricted than GPT‐5 Codex, especially for devs using it to automate deploys or infrastructure.

Question 4

What is OpenAI Codex used for?

Accepted Answer

Codex helps our teams get up to speed quickly in unfamiliar parts of the codebase when onboarding, debugging, or investigating an incident. They often use Codex to locate the core logic of a feature, map out relationships between services or modules, and trace data flow through a system.

Question 5

Is OpenAI codex free to use?

Accepted Answer

Running models locally is the most independent route to use Codex for free. Using Ollama, you pull a model (for example, a Mistral variant), run the local server, and point Codex CLI to the local provider.

OpenAI: GPT-5.1-Codex-Max

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