Codex Models

Recommended models

gpt-5.3-codex

Most capable agentic coding model to date, combining frontier coding performance with stronger reasoning and professional knowledge capabilities.

codex -m gpt-5.3-codex

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Capability

Speed

Codex CLI & SDK

Codex app & IDE extension

Codex Cloud

ChatGPT Credits

API Access

gpt-5.3-codex-spark

Text-only research preview model optimized for near-instant, real-time coding iteration. Available to ChatGPT Pro users.

codex -m gpt-5.3-codex-spark

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Capability

Speed

Codex CLI & SDK

Codex app & IDE extension

Codex Cloud

ChatGPT Credits

API Access

The gpt-5.3-codex-spark model is available in research preview for ChatGPT Pro subscribers. It is optimized for near-instant, real-time coding iteration.

Alternative models

gpt-5.2-codex

Advanced coding model for real-world engineering. Succeeded by GPT-5.3-Codex.

codex -m gpt-5.2-codex

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gpt-5.2

Our best general agentic model for tasks across industries and domains.

codex -m gpt-5.2

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gpt-5.1-codex-max

Optimized for long-horizon, agentic coding tasks in Codex.

codex -m gpt-5.1-codex-max

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gpt-5.1

Great for coding and agentic tasks across domains. Succeeded by GPT-5.2.

codex -m gpt-5.1

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gpt-5.1-codex

Optimized for long-running, agentic coding tasks in Codex. Succeeded by GPT-5.1-Codex-Max.

codex -m gpt-5.1-codex

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gpt-5-codex

Version of GPT-5 tuned for long-running, agentic coding tasks. Succeeded by GPT-5.1-Codex.

codex -m gpt-5-codex

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gpt-5-codex-mini

Smaller, more cost-effective version of GPT-5-Codex. Succeeded by GPT-5.1-Codex-Mini.

codex -m gpt-5-codex

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gpt-5

Reasoning model for coding and agentic tasks across domains. Succeeded by GPT-5.1.

codex -m gpt-5

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Other models

Codex works best with the models listed above.

You can also point Codex at any model and provider that supports either the Chat Completions or Responses APIs to fit your specific use case.

Support for the Chat Completions API is deprecated and will be removed in future releases of Codex.

Configuring models

Configure your default local model

The Codex CLI and IDE extension use the same config.toml configuration file. To specify a model, add a model entry to your configuration file. If you don't specify a model, the Codex app, CLI, or IDE Extension defaults to a recommended model.

model = "gpt-5.2"

Choosing a different local model temporarily

In the Codex CLI, you can use the /model command during an active thread to change the model. In the IDE extension, you can use the model selector below the input box to choose your model.

To start a new Codex CLI thread with a specific model or to specify the model for codex exec you can use the --model/-m flag:

codex -m gpt-5.3-codex

Choosing your model for cloud tasks

Currently, you can't change the default model for Codex cloud tasks.