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MicrosoftCurrent

GPT-5.1 Codex Max

Maximum reasoning effort code model with extended capabilities.

Context Window

400K tokens

≈ 300K words

Input Price

$1.25

per 1M tokens

Output Price

$10

per 1M tokens

Released

December 2025

Capabilities

Vision / Image inputTool / Function calling

Best for

Maximum performance coding model with extra-high reasoning effort support for complex development tasks.

Strengths

  • Advanced coding
  • Code generation
  • Software engineering
  • Debugging

API identifier

gpt-5.1-codex-max

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