GPT-5.1-CODEX
GPT-5.1-Codex is a specialized version of GPT-5.1 optimized for software engineering and coding workflows. It is designed for both interactive development sessions and long, independent execution of complex engineering tasks.
Input
Output
Context
400K
Max Output
128K
Parameters
—
Technical Specifications
Model TypeChat
Context Window400K
Max Output Tokens128K
Parameters—
Training Cutoff—
Licenseproprietary
Capabilities
Input Modalities
textimage
Output Modalities
text
Features
agenticcode_completioncode_generationcode_reviewfunction_callingjson_modereasoningstreamingtool_usevision
Benchmarks
23.4%
HLE
86.0%
GPQA
40.2%
SciCode
86.0%
MMLU Pro
95.7
Math
36.6
Coding
84.9%
LiveCodeBench
43.1
Intelligence
159
Speed (tok/s)
5.9
TTFA (s)
5.9
TTFT (s)
Resources & Links
proprietary — Proprietary - API access only
Related Tools
Data sourced from official provider APIs and documentation
Last updated: May 5, 2026
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