GPT-5.1 Codex
GPT-5.1 Codex is a version of GPT-5.1 optimized for agentic coding tasks in Codex or similar environments. It features higher reasoning capabilities and is available in the Responses API. The underlying model snapshot is regularly updated.
Benchmark results
| Benchmark | Score | Tags | Source |
|---|---|---|---|
| SWE-Bench Verified | 73.7% | self-reported llm-stats | link → |
| SWE-Lancer | 66.3% | self-reported llm-stats | link → |
| Terminal-Bench 2.0 | 52.8% | self-reported llm-stats | link → |