models.md Codex Docs, 2026-04-17 00:44 UTC → 2026-04-29 12:40 UTC

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3## Recommended models3## Recommended models

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5![gpt-5.5](/images/api/models/gpt-5.5.jpg)

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7gpt-5.5

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9OpenAI's newest frontier model for complex coding, computer use, knowledge work, and research workflows in Codex.

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11codex -m gpt-5.5

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13Copy command

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15Capability

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17Speed

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19Codex CLI & SDK

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21Codex app & IDE extension

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23Codex Cloud

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25ChatGPT Credits

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27API Access

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5![gpt-5.4](/images/api/models/gpt-5.4.jpg)29![gpt-5.4](/images/api/models/gpt-5.4.jpg)

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7gpt-5.431gpt-5.4

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99API Access123API Access

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101For most tasks in Codex, start with `gpt-5.4`. It combines strong coding,125For most tasks in Codex, start with `gpt-5.5` when it appears in your model

102reasoning, native computer use, and broader professional workflows in one126 picker. It is strongest for complex coding, computer use, knowledge work, and

103model. Use `gpt-5.4-mini` when you want a faster, lower-cost option for127 research workflows. GPT-5.5 is currently available in Codex when you sign in

104lighter coding tasks or subagents. The `gpt-5.3-codex-spark` model is128 with ChatGPT; it isn't available with API-key authentication. During the

105available in research preview for ChatGPT Pro subscribers and is optimized for129 rollout, continue using `gpt-5.4` if `gpt-5.5` is not yet available. Use

106near-instant, real-time coding iteration.130 `gpt-5.4-mini` when you want a faster, lower-cost option for lighter coding

131 tasks or subagents. The `gpt-5.3-codex-spark` model is available in research

132 preview for ChatGPT Pro subscribers and is optimized for near-instant,

133 real-time coding iteration.

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108## Alternative models135## Alternative models

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135The Codex CLI and IDE extension use the same `config.toml` [configuration file](https://developers.openai.com/codex/config-basic). 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.162The Codex CLI and IDE extension use the same `config.toml` [configuration file](https://developers.openai.com/codex/config-basic). 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.

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137```164```toml

138model = "gpt-5.4"165model = "gpt-5.5"

139```166```

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168If `gpt-5.5` isn't available in your account yet, use `gpt-5.4`.

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141### Choosing a different local model temporarily170### Choosing a different local model temporarily

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143In 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.172In 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.

145To 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:174To 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:

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147```bash176```bash

148codex -m gpt-5.4177codex -m gpt-5.5

149```178```

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151### Choosing your model for cloud tasks180### Choosing your model for cloud tasks